Patent Publication Number: US-11645892-B2

Title: Persistent symbol position arrays with array growth in both base game and feature game

Description:
RELATED APPLICATIONS 
     This application is a continuation application under 35 U.S.C. § 120 of U.S. patent application Ser. No. 17/248,504, filed Jan. 27, 2021, and titled “PERSISTENT SYMBOL POSITION ARRAYS WITH ARRAY GROWTH IN BOTH BASE GAME AND FEATURE GAME,” which is hereby incorporated herein by reference in its entirety and for all purposes. 
    
    
     BACKGROUND 
     Electronic gaming machines (“EGMs”) or gaming devices provide a variety of wagering games such as slot games, video poker games, video blackjack games, roulette games, video bingo games, keno games and other types of games that are frequently offered at casinos and other locations. Play on EGMs typically involves a player establishing a credit balance by inputting money, or another form of monetary credit, and placing a monetary wager (from the credit balance) on one or more outcomes of an instance (or single play) of a primary or base game. In some cases, a player may qualify for a special mode of the base game, a secondary game, or a bonus round of the base game by attaining a certain winning combination or triggering event in, or related to, the base game, or after the player is randomly awarded the special mode, secondary game, or bonus round. In the special mode, secondary game, or bonus round, the player is given an opportunity to win extra game credits, game tokens or other forms of payout. In the case of “game credits” that are awarded during play, the game credits are typically added to a credit meter total on the EGM and can be provided to the player upon completion of a gaming session or when the player wants to “cash out.” 
     “Slot” type games are often displayed to the player in the form of various symbols arrayed in a row-by-column grid or matrix. Specific matching combinations of symbols along predetermined paths (or paylines) through the matrix indicate the outcome of the game. The display typically highlights winning combinations/outcomes for identification by the player. Matching combinations and their corresponding awards are usually shown in a “pay-table” which is available to the player for reference. Often, the player may vary his/her wager to include differing numbers of paylines and/or the amount bet on each line. By varying the wager, the player may sometimes alter the frequency or number of winning combinations, frequency or number of secondary games, and/or the amount awarded. 
     Typical games use a random number generator (RNG) to randomly determine the outcome of each game. The game is designed to return a certain percentage of the amount wagered back to the player over the course of many plays or instances of the game, which is generally referred to as return to player (RTP). The RTP and randomness of the RNG ensure the fairness of the games and are highly regulated. Upon initiation of play, the RNG randomly determines a game outcome and symbols are then selected which correspond to that outcome. Notably, some games may include an element of skill on the part of the player and are therefore not entirely random. 
     SUMMARY 
     The present disclosure is directed to various implementations in which a main game is configured to include an array growth feature that allows an array of symbol positions used to display symbols during game play of the main game to be increased in size in one dimension during game play responsive to satisfaction of an array growth condition. In such implementations, the main game is also configured to cause a feature game to be presented responsive to a feature game trigger condition being met—the feature game that is presented uses an array of symbol positions that has first and second dimensions that are the same as the first and second dimensions of the array of symbol positions in use in the main game at the time the feature game trigger condition was met. 
     In some implementations, a system may be provided that includes one or more displays and a game controller that includes one or more processors and one or more memory devices. The one or more processors, the one or more memory devices, and the one or more displays may be operably connected, and the one or more memory devices may store computer-executable instructions which, when executed, may control the one or more processors to cause an array of symbol positions to be displayed on the one or more displays. The array of symbol positions may be defined by a first dimension A and a second dimension B. The one or more memory devices may further store computer-executable instructions which, when executed, may further control the one or more processors to, responsive to each receipt of a first input signal indicative of a game play of a main game, select, in association with that game play of the main game, a symbol for each symbol position in the array of symbol positions from one of one or more sets of symbols associated with the main game; display, in each symbol position, the symbol selected for that symbol position in association with that game play of the main game; determine whether any of the symbols selected for display in association with that game play is an array growth symbol or are array growth symbols that, in being displayed, meet an array growth condition; cause, responsive to determining that the array growth condition is met, the second dimension of the array of symbol positions to increment by 1, thereby causing a quantity of additional symbol positions equal to the first dimension to be additionally displayed as part of the array of symbol positions, and additional symbols from the one set of symbols of the one or more sets of symbols to be displayed in the additionally displayed symbol positions; determine whether any of the symbols selected for display in association with that game play is a feature game trigger symbol or are feature game trigger symbols that, in being displayed, meet a feature game trigger condition; cause, responsive to determining that the feature game trigger condition is met, a feature game to be presented using the array of symbol positions, inclusive of any of the additionally displayed symbol positions; and determine, responsive to receipt of one or more second input signals and in association with the presentation of the feature game, an outcome of the feature game, wherein each second input signal is indicative of a feature game play of the feature game. 
     In some such implementations, the feature game may be a hold and spin game that causes symbols to be displayed in the array of symbol positions, inclusive of any additionally displayed symbol positions. 
     In some implementations, the one or more memory devices may store further computer-executable instructions which, when executed, may further control the one or more processors to, responsive to each receipt of the second input signal indicative of a feature game play of the feature game, select, in association with that feature game play, a symbol for at least each symbol position in the array of symbol positions that does not display a feature game symbol from one of one or more sets of symbols associated with the feature game; display, in each symbol position in the array of symbol positions that does not display a feature game symbol and for that feature game play, the symbol selected for that symbol position in association with that feature game play; determine whether any of the symbols selected for display in association with that feature game play is an array growth symbol or are array growth symbols that, in being displayed, meet the array growth condition; cause, responsive to determining that the array growth condition is met, the second dimension of the array of symbol positions to increment by 1, thereby causing a quantity of additional symbol positions equal to the first dimension to be additionally displayed as part of the array of symbol positions, and additional symbols from the one set of symbols of the one or more sets of symbols to be displayed in the additionally displayed symbol positions; identify any symbols that are newly displayed as a result of that feature game play that are a feature game symbol; decrement, responsive to determining that the identified feature game symbols for that feature game play, if any, do not meet a remaining play counter reset condition, a remaining play counter; and increment, responsive to determining that the identified feature game symbols for that feature game play, if any, meet the remaining play counter reset condition, the remaining play counter by 0 or more units. 
     In some such implementations, the feature game symbols and the feature game trigger symbols may be the same symbols and may be displayed in the same symbol positions in the array of symbol positions when the feature game is presented responsive to the feature game trigger condition being met as they were in the main game when the feature game trigger condition was met. 
     In some implementations, the one or more memory devices may store further computer-executable instructions which, when executed, may further control the one or more processors to determine, responsive to receipt of one of the one or more second input signals, that the feature game has concluded, and reset, in association with the conclusion of the feature game, the array of symbol positions to a default size that does not include any symbol positions that were added responsive to the array growth condition being met. 
     In some implementations, each set of symbols may be divided into multiple subsets of symbols, the array of symbol positions may include a plurality of sets of symbol positions, the symbol positions in each set of symbol positions may be associated with array positions that have a corresponding common index value for the first dimension of the array, and the symbols selected for symbol positions in each set of symbol positions may be selected from a corresponding one of the subsets of symbols. 
     In some implementations, the symbols in each subset of symbols may be associated with information that defines a predetermined sequence for those symbols in which a first symbol in the predetermined sequence is treated as being sequentially adjacent to both a second symbol in the predetermined sequence and a last symbol in the predetermined sequence and in which the last symbol in the predetermined sequence is treated as being sequentially adjacent to both the first symbol in the predetermined sequence and a penultimate symbol in the predetermined sequence. In such implementations, the one or more memory devices may store further computer-executable instructions which, when executed, further control the one or more processors to select the symbols for each set of symbol positions such that the selected symbols, when displayed in those symbol positions, are displayed in an order that is consistent with the predetermined sequence of the symbols in the corresponding subset for that set of symbol positions and such that the symbols from the corresponding subset are sequentially adjacent within the predetermined sequence. 
     In some such implementations, the one or more memory devices may store further computer-executable instructions which, when executed, further control the one or more processors to cause the second dimension B of the array to not exceed a predetermined maximum value X. 
     In some further such implementations, the predetermined sequence of symbols for at least one of the subsets of symbols may include at least one instance of X or more sequentially adjacent feature game trigger symbols. 
     In some additional or alternative such implementations, the feature game trigger condition may be that the feature game trigger symbols are displayed in X or more symbol positions of the array of symbol positions. 
     In some implementations, a method is provided that includes controlling one or more processors to cause an array of symbol positions to be displayed on one or more displays. The array of symbol positions may be defined by a first dimension A and a second dimension B. The method may further include receiving one or more first input signals by the one or more processors, each indicative of a game play of a main game, and, responsive to each receipt thereof, selecting, in association with that game play of the main game and by the one or more processors, a symbol for each symbol position in the array of symbol positions from one of one or more sets of symbols associated with the main game; causing, by the one or more processors, the display, in each symbol position, of the symbol selected for that symbol position in association with that game play of the main game; determining, by the one or more processors, whether any of the symbols selected for display in association with that game play is an array growth symbol or are array growth symbols that, in being displayed, meet an array growth condition; causing, responsive to determining that the array growth condition is met and by the one or more processors, the second dimension of the array of symbol positions to increment by 1, thereby causing a quantity of additional symbol positions equal to the first dimension to be additionally displayed as part of the array of symbol positions, and additional symbols from the one set of symbols of the one or more sets of symbols to be displayed in the additionally displayed symbol positions; determining, by the one or more processors, whether any of the symbols selected for display in association with that game play is a feature game trigger symbol or are feature game trigger symbols that, in being displayed, meet a feature game trigger condition; causing, responsive to determining that the feature game trigger condition is met and by the one or more processors, a feature game to be presented using the array of symbol positions, inclusive of any of the additionally displayed symbol positions, and determining, responsive to receipt of one or more second input signals, in association with the presentation of the feature game, and by the one or more processors, an outcome of the feature game, wherein each second input signal is indicative of a feature game play of the feature game. 
     In some implementations, the feature game may be a hold and spin game in which symbols are displayed in the array of symbol positions, inclusive of any additionally displayed symbol positions. 
     In some implementations, the method may further include, responsive to each receipt of the second input signal indicative of a feature game play of the feature game, selecting, in association with that feature game play and by the one or more processors, a symbol for at least each symbol position in the array of symbol positions that does not display a feature game symbol from one of one or more sets of symbols associated with the feature game; causing, by the one or more processors, the display, in each symbol position in the array of symbol positions that does not display a feature game symbol and for that feature game play, the symbol selected for that symbol position in association with that feature game play; determining, by the one or more processors, that at least one of the symbols selected for display in association with that feature game play is an array growth symbol or are array growth symbols that, in being displayed, meet the array growth condition; causing, responsive to determining that the array growth condition is met and by the one or more processors, the second dimension of the array of symbol positions to increment by 1, thereby causing a quantity of additional symbol positions equal to the first dimension to be additionally displayed as part of the array of symbol positions, and additional symbols from the one set of symbols of the one or more sets of symbols to be displayed in the additionally displayed symbol positions; identifying, by the one or more processors, any symbols that are newly displayed as a result of that feature game play that are a feature game symbol; decrement, by the one or more processors and responsive to determining that the identified feature game symbols for that feature game play, if any, do not meet a remaining play counter reset condition, a remaining play counter, and increment, by the one or more processors and responsive to determining that the identified feature game symbols for that feature game play, if any, meet the remaining play counter reset condition, the remaining play counter by 0 or more units. 
     In some implementations, the feature game symbols and the feature game trigger symbols may be the same symbols and may be displayed in the same symbol positions in the array of symbol positions when the feature game is presented responsive to the feature game trigger condition being met as they were in the main game when the feature game trigger condition was met. 
     In some implementations, the method may further include determining, responsive to receipt of one of the one or more second input signals and by the one or more processors, that the feature game has concluded, and resetting, in association with the conclusion of the feature game and by the one or more processors, the array of symbol positions to a default size that does not include any symbol positions that were added responsive to the array growth condition being met. 
     In some implementations, each set of symbols may be divided into multiple subsets of symbols, the array of symbol positions may include a plurality of sets of symbol positions, the symbol positions in each set of symbol positions may be associated with array positions that have a corresponding common index value for the first dimension of the array, and the symbols selected for symbol positions in each set of symbol positions may be selected from a corresponding one of the subsets of symbols. 
     In some such implementations, the symbols in each subset of symbols may be associated with information that defines a predetermined sequence for those symbols in which a first symbol in the predetermined sequence is treated as being sequentially adjacent to both a second symbol in the predetermined sequence and a last symbol in the predetermined sequence and in which the last symbol in the predetermined sequence is treated as being sequentially adjacent to both the first symbol in the predetermined sequence and a penultimate symbol in the predetermined sequence. In such implementations, the method may further include selecting, by the one or more processors, the symbols for each set of symbol positions such that the selected symbols, when displayed in those symbol positions, are displayed in an order that is consistent with the predetermined sequence of the symbols in the corresponding subset for that set of symbol positions and such that the symbols from the corresponding subset are sequentially adjacent within the predetermined sequence. 
     In some such implementations, the method may further include causing, by the one or more processors, the second dimension B of the array to not exceed a predetermined maximum value X. 
     In some further such implementations, the predetermined sequence of symbols for at least one of the subsets of symbols may include at least one instance of X or more sequentially adjacent feature game trigger symbols. 
     In some additional or alternative such, implementations, the feature game trigger condition may be that the feature game trigger symbols are displayed in X or more symbol positions of the array of symbol positions. 
     In some implementations, a non-transitory, computer-readable medium may be provided that stores computer-executable instructions which, when executed by one or more processors, control the one or more processors to cause an array of symbol positions to be displayed on one or more displays. The array of symbol positions may be defined by a first dimension A and a second dimension B. The non-transitory, computer-readable medium may further store additional computer-executable instructions which, when executed by one or more processors, further control the one or more processors to, responsive to each receipt of a first input signal indicative of a game play of a main game, select, in association with that game play of the main game, a symbol for each symbol position in the array of symbol positions from one of one or more sets of symbols associated with the main game; display, in each symbol position, the symbol selected for that symbol position in association with that game play of the main game; determine whether any of the symbols selected for display in association with that game play is an array growth symbol or are array growth symbols that, in being displayed, meet an array growth condition; cause, responsive to determining that the array growth condition is met, the second dimension of the array of symbol positions to increment by 1, thereby causing a quantity of additional symbol positions equal to the first dimension to be additionally displayed as part of the array of symbol positions, and additional symbols from the one set of symbols of the one or more sets of symbols to be displayed in the additionally displayed symbol positions; determine whether any of the symbols selected for display in association with that game play is a feature game trigger symbol or are feature game trigger symbols that, in being displayed, meet a feature game trigger condition; cause, responsive to determining that the feature game trigger condition is met, a feature game to be presented using the array of symbol positions, inclusive of any of the additionally displayed symbol positions; and determine, responsive to receipt of one or more second input signals and in association with the presentation of the feature game, an outcome of the feature game, wherein each second input signal is indicative of a feature game play of the feature game. 
     In some implementations, the feature game may be a hold and spin game that causes symbols to be displayed in the array of symbol positions, inclusive of any additionally displayed symbol positions. 
     In some implementations, the non-transitory, computer-readable medium may further store additional computer-executable instructions which, when executed by one or more processors, may further control the one or more processors to, responsive to each receipt of the second input signal indicative of a feature game play of the feature game, select, in association with that feature game play, a symbol for at least each symbol position in the array of symbol positions that does not display a feature game symbol from one of one or more sets of symbols associated with the feature game; display, in each symbol position in the array of symbol positions that does not display a feature game symbol and for that feature game play, the symbol selected for that symbol position in association with that feature game play; determine whether any of the symbols selected for display in association with that feature game play is an array growth symbol or are array growth symbols that, in being displayed, meet the array growth condition; cause, responsive to determining that the array growth condition is met, the second dimension of the array of symbol positions to increment by 1, thereby causing a quantity of additional symbol positions equal to the first dimension to be additionally displayed as part of the array of symbol positions, and additional symbols from the one set of symbols of the one or more sets of symbols to be displayed in the additionally displayed symbol positions; identify any symbols that are newly displayed as a result of that feature game play that are a feature game symbol; decrement, responsive to determining that the identified feature game symbols for that feature game play, if any, do not meet a remaining play counter reset condition, a remaining play counter; and increment, responsive to determining that the identified feature game symbols for that feature game play, if any, meet the remaining play counter reset condition, the remaining play counter by 0 or more units. 
     In some such implementations, the feature game symbols and the feature game trigger symbols may be the same symbols and may be caused by the computer-executable instructions to be displayed in the same symbol positions in the array of symbol positions when the feature game is presented responsive to the feature game trigger condition being met as they were in the main game when the feature game trigger condition was met. 
     In some implementations, the non-transitory, computer-readable medium may further store additional computer-executable instructions which, when executed by one or more processors, may further control the one or more processors to, determine, responsive to receipt of one of the one or more second input signals, that the feature game has concluded, and reset, in association with the conclusion of the feature game, the array of symbol positions to a default size that does not include any symbol positions that were added responsive to the array growth condition being met. 
     In some implementations, each set of symbols may be divided into multiple subsets of symbols, the array of symbol positions may include a plurality of sets of symbol positions, the symbol positions in each set of symbol positions may be associated with array positions that have a corresponding common index value for the first dimension of the array, and the symbols selected for symbol positions in each set of symbol positions may be selected from a corresponding one of the subsets of symbols. 
     In some such implementations, the symbols in each subset of symbols may be associated with information that defines a predetermined sequence for those symbols in which a first symbol in the predetermined sequence is treated as being sequentially adjacent to both a second symbol in the predetermined sequence and a last symbol in the predetermined sequence and in which the last symbol in the predetermined sequence is treated as being sequentially adjacent to both the first symbol in the predetermined sequence and a penultimate symbol in the predetermined sequence. In such implementations, the non-transitory, computer-readable medium may further store additional computer-executable instructions which, when executed by one or more processors, may further control the one or more processors to select the symbols for each set of symbol positions such that the selected symbols, when displayed in those symbol positions, are displayed in an order that is consistent with the predetermined sequence of the symbols in the corresponding subset for that set of symbol positions and such that the symbols from the corresponding subset are sequentially adjacent within the predetermined sequence. 
     In some further such implementations, the non-transitory, computer-readable medium may further store additional computer-executable instructions which, when executed by one or more processors, may further control the one or more processors to cause the second dimension B of the array to not exceed a predetermined maximum value X. 
     In some such implementations, the predetermined sequence of symbols for at least one of the subsets of symbols may include at least one instance of X or more sequentially adjacent feature game trigger symbols. 
     In some additional or alternative such implementations, the feature game trigger condition may be that the feature game trigger symbols are displayed in X or more symbol positions of the array of symbol positions. 
     These and other implementations will be evident from the disclosure provided herein. The above-listed implementations are not an exclusive listing of implementations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is an exemplary diagram showing several EGMs networked with various gaming related servers. 
         FIG.  2 A  is a block diagram showing various functional elements of an exemplary EGM. 
         FIG.  2 B  depicts a casino gaming environment according to one example. 
         FIG.  2 C  is a diagram that shows examples of components of a system for providing online gaming according to some aspects of the present disclosure. 
         FIG.  3    illustrates, in block diagram form, an implementation of a game processing architecture algorithm that implements a game processing pipeline for the play of a game in accordance with various implementations described herein. 
         FIG.  4    depicts a flow chart of main game play for a main game featuring persistent array growth for an array of symbol positions. 
         FIG.  5    depicts a flow chart of feature game play for a feature game that uses an array of symbol positions inherited from a main game having persistent array growth for an array of symbol positions. 
         FIG.  6    depicts an example GUI for a main game including a persistent array growth mechanism for an array of symbol positions. 
         FIG.  7    depicts the example GUI of  FIG.  6    in an example game state for the main game in which an array growth symbol is displayed in one of the symbol positions. 
         FIG.  8    depicts the example GUI of  FIG.  6    after a second dimension of the array of symbol positions has been increased by one unit. 
         FIG.  9    depicts the example GUI of  FIG.  8    after feature game trigger symbols meeting a feature game trigger condition have been displayed. 
         FIG.  10    depicts the example GUI of  FIG.  8    after another set of feature game trigger symbols meeting the feature game trigger condition have been displayed. 
         FIG.  11    depicts an example GUI for a feature game that is initialized based on the main game state shown in the example GUI of  FIG.  9   . 
         FIG.  12    depicts the example GUI of  FIG.  11    after a play of the feature game. 
         FIG.  13    depicts the example GUI of  FIG.  11    after another play of the feature game in which an array growth symbol is displayed in one of the symbol positions. 
         FIG.  14    depicts the example GUI of  FIG.  11    after the second dimension of the array of symbol positions has been increased by one unit. 
         FIG.  15    depicts the example GUI of  FIG.  14    after a further play of the feature game in which another feature game trigger symbol has been newly displayed in the GUI. 
         FIG.  16    depicts the example GUI of  FIG.  14    after the feature game play has concluded due to the available play counter being decremented to zero. 
         FIG.  17    depicts the example GUI of  FIG.  14    after the feature game play has concluded due to all of the symbol positions being filled with feature game trigger symbols. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure is directed to various implementations in which a main game is configured to include an array growth feature that allows an array of symbol positions used to display symbols during game play of the main game to be increased in size in one dimension during game play responsive to satisfaction of an array growth condition. In such implementations, the main game is also configured to cause a feature game to be presented responsive to a feature game trigger condition being met—the feature game that is presented uses an array of symbol positions that has first and second dimensions that are the same as the first and second dimensions of the array of symbol positions in use in the main game at the time the feature game trigger condition was met. Such configurations are able to maintain player interest, and thus potential revenue streams resulting from game play, more effectively since a player that is playing the main game while the main game is displaying an increased-size array of symbol positions is will likely wish to continue playing knowing that a) their chances of triggering the feature game are likely increased due to the larger array size and b) that their chances of achieving a higher reward from the feature game, should it be triggered, will also be increased due to the increased array size. Moreover, such implementations may also allow for additional array growth during the feature game as well, thus building further on array growth that may occur during play of the main game. 
     The main games and feature games that are discussed below may both be described as being symbol-based games in which symbols are selected for display in an array of symbol positions presented to a player via a GUI as part of each play of the relevant game. Each symbol position is thus caused to display a corresponding symbol for each instance of game play. Various specific details of a variety of example implementations are discussed below with respect to the Figures. 
     Main/feature games with persistent arrays of symbol positions provide a new game play experience for players in which “improvements” (array growth) that occur in the main game may persist and carry over into the feature game should the feature game be triggered. At the same time, each improvement that occurs in the main game may increase the odds of further improvements and/or feature game triggering, which serves to incentivize the player and encourage them to keep playing. 
       FIG.  1    illustrates several different models of EGMs which may be networked to various gaming related servers. Shown is a system  100  in a gaming environment including one or more server computers  102  (e.g., slot servers of a casino) that are in communication, via a communications network, with one or more gaming devices  104 A- 104 X (EGMs, slots, video poker, bingo machines, etc.) that can implement one or more aspects of the present disclosure. The gaming devices  104 A- 104 X may alternatively be portable and/or remote gaming devices such as, but not limited to, a smart phone, a tablet, a laptop, or a game console. Gaming devices  104 A- 104 X utilize specialized software and/or hardware to form non-generic, particular machines or apparatuses that comply with regulatory requirements regarding devices used for wagering or games of chance that provide monetary awards. 
     Communication between the gaming devices  104 A- 104 X and the server computers  102 , and among the gaming devices  104 A- 104 X, may be direct or indirect using one or more communication protocols. As an example, gaming devices  104 A- 104 X and the server computers  102  can communicate over one or more communication networks, such as over the Internet through a website maintained by a computer on a remote server or over an online data network including commercial online service providers, Internet service providers, private networks (e.g., local area networks and enterprise networks), and the like (e.g., wide area networks). The communication networks could allow gaming devices  104 A- 104 X to communicate with one another and/or the server computers  102  using a variety of communication-based technologies, such as radio frequency (RF) (e.g., wireless fidelity (WiFi®) and Bluetooth®), cable TV, satellite links and the like. 
     In some implementation, server computers  102  may not be necessary and/or preferred. For example, in one or more implementations, a stand-alone gaming device such as gaming device  104 A, gaming device  104 B or any of the other gaming devices  104 C- 104 X can implement one or more aspects of the present disclosure. However, it is typical to find multiple EGMs connected to networks implemented with one or more of the different server computers  102  described herein. 
     The server computers  102  may include a central determination gaming system server  106 , a ticket-in-ticket-out (TITO) system server  108 , a player tracking system server  110 , a progressive system server  112 , and/or a casino management system server  114 . Gaming devices  104 A- 104 X may include features to enable operation of any or all servers for use by the player and/or operator (e.g., the casino, resort, gaming establishment, tavern, pub, etc.). For example, game outcomes may be generated on a central determination gaming system server  106  and then transmitted over the network to any of a group of remote terminals or remote gaming devices  104 A- 104 X that utilize the game outcomes and display the results to the players. 
     Gaming device  104 A is often of a cabinet construction which may be aligned in rows or banks of similar devices for placement and operation on a casino floor. The gaming device  104 A often includes a main door which provides access to the interior of the cabinet. Gaming device  104 A typically includes a button area or button deck  120  accessible by a player that is configured with input switches or buttons  122 , an access channel for a bill validator  124 , and/or an access channel for a ticket-out printer  126 . 
     In  FIG.  1   , gaming device  104 A is shown as a Relm XL™ model gaming device manufactured by Aristocrat® Technologies, Inc. As shown, gaming device  104 A is a reel machine having a gaming display area  118  comprising a number (typically 3 or 5) of mechanical reels  130  with various symbols displayed on them. The mechanical reels  130  are independently spun and stopped to show a set of symbols within the gaming display area  118  which may be used to determine an outcome to the game. 
     In many configurations, the gaming device  104 A may have a main display  128  (e.g., video display monitor) mounted to, or above, the gaming display area  118 . The main display  128  can be a high-resolution liquid crystal display (LCD), plasma, light emitting diode (LED), or organic light emitting diode (OLED) panel which may be flat or curved as shown, a cathode ray tube, or other conventional electronically controlled video monitor. 
     In some implementations, the bill validator  124  may also function as a “ticket-in” reader that allows the player to use a casino issued credit ticket to load credits onto the gaming device  104 A (e.g., in a cashless ticket (“TITO”) system). In such cashless implementations, the gaming device  104 A may also include a “ticket-out” printer  126  for outputting a credit ticket when a “cash out” button is pressed. Cashless TITO systems are used to generate and track unique bar-codes or other indicators printed on tickets to allow players to avoid the use of bills and coins by loading credits using a ticket reader and cashing out credits using a ticket-out printer  126  on the gaming device  104 A. The gaming device  104 A can have hardware meters for purposes including ensuring regulatory compliance and monitoring the player credit balance. In addition, there can be additional meters that record the total amount of money wagered on the gaming device, total amount of money deposited, total amount of money withdrawn, total amount of winnings on gaming device  104 A. 
     In some implementations, a player tracking card reader  144 , a transceiver for wireless communication with a mobile device (e.g., a player&#39;s smartphone), a keypad  146 , and/or an illuminated display  148  for reading, receiving, entering, and/or displaying player tracking information is provided in gaming device  104 A. In such implementations, a game controller within the gaming device  104 A can communicate with the player tracking system server  110  to send and receive player tracking information. 
     Gaming device  104 A may also include a bonus topper wheel  134 . When bonus play is triggered (e.g., by a player achieving a particular outcome or set of outcomes in the primary game), bonus topper wheel  134  is operative to spin and stop with indicator arrow  136  indicating the outcome of the bonus game. Bonus topper wheel  134  is typically used to play a bonus game, but it could also be incorporated into play of the base or primary game. 
     A candle  138  may be mounted on the top of gaming device  104 A and may be activated by a player (e.g., using a switch or one of buttons  122 ) to indicate to operations staff that gaming device  104 A has experienced a malfunction or the player requires service. The candle  138  is also often used to indicate a jackpot has been won and to alert staff that a hand payout of an award may be needed. 
     There may also be one or more information panels  152  which may be a back-lit, silkscreened glass panel with lettering to indicate general game information including, for example, a game denomination (e.g., $0.25 or $1), pay lines, pay tables, and/or various game related graphics. In some implementations, the information panel(s)  152  may be implemented as an additional video display. 
     Gaming devices  104 A have traditionally also included a handle  132  typically mounted to the side of main cabinet  116  which may be used to initiate game play. 
     Many or all the above described components can be controlled by circuitry (e.g., a game controller) housed inside the main cabinet  116  of the gaming device  104 A, the details of which are shown in  FIG.  2 A . 
     An alternative example gaming device  104 B illustrated in  FIG.  1    is the Arc™ model gaming device manufactured by Aristocrat® Technologies, Inc. Note that where possible, reference numerals identifying similar features of the gaming device  104 A implementation are also identified in the gaming device  104 B implementation using the same reference numbers. Gaming device  104 B does not include physical reels and instead shows game play functions on main display  128 . An optional topper screen  140  may be used as a secondary game display for bonus play, to show game features or attraction activities while a game is not in play, or any other information or media desired by the game designer or operator. In some implementations, the optional topper screen  140  may also or alternatively be used to display progressive jackpot prizes available to a player during play of gaming device  104 B. 
     Example gaming device  104 B includes a main cabinet  116  including a main door which opens to provide access to the interior of the gaming device  104 B. The main or service door is typically used by service personnel to refill the ticket-out printer  126  and collect bills and tickets inserted into the bill validator  124 . The main or service door may also be accessed to reset the machine, verify and/or upgrade the software, and for general maintenance operations. 
     Another example gaming device  104 C shown is the Helix™ model gaming device manufactured by Aristocrat® Technologies, Inc. Gaming device  104 C includes a main display  128 A that is in a landscape orientation. Although not illustrated by the front view provided, the main display  128 A may have a curvature radius from top to bottom, or alternatively from side to side. In some implementations, main display  128 A is a flat panel display. Main display  128 A is typically used for primary game play while secondary display  128 B is typically used for bonus game play, to show game features or attraction activities while the game is not in play or any other information or media desired by the game designer or operator. In some implementations, example gaming device  104 C may also include speakers  142  to output various audio such as game sound, background music, etc. 
     Many different types of games, including mechanical slot games, video slot games, video poker, video blackjack, video pachinko, keno, bingo, and lottery, may be provided with or implemented within the depicted gaming devices  104 A- 104 C and other similar gaming devices. Each gaming device may also be operable to provide many different games. Games may be differentiated according to themes, sounds, graphics, type of game (e.g., slot game vs. card game vs. game with aspects of skill), denomination, number of paylines, maximum jackpot, progressive or non-progressive, bonus games, and may be deployed for operation in Class 2 or Class 3, etc. 
       FIG.  2 A  is a block diagram depicting exemplary internal electronic components of a gaming device  200  connected to various external systems. All or parts of the gaming device  200  shown could be used to implement any one of the example gaming devices  104 A-X depicted in  FIG.  1   . As shown in  FIG.  2 A , gaming device  200  includes a topper display  216  or another form of a top box (e.g., a topper wheel, a topper screen, etc.) that sits above cabinet  218 . Cabinet  218  or topper display  216  may also house a number of other components which may be used to add features to a game being played on gaming device  200 , including speakers  220 , a ticket printer  222  which prints bar-coded tickets or other media or mechanisms for storing or indicating a player&#39;s credit value, a ticket reader  224  which reads bar-coded tickets or other media or mechanisms for storing or indicating a player&#39;s credit value, and a player tracking interface  232 . Player tracking interface  232  may include a keypad  226  for entering information, a player tracking display  228  for displaying information (e.g., an illuminated or video display), a card reader  230  for receiving data and/or communicating information to and from media or a device such as a smart phone enabling player tracking.  FIG.  2    also depicts utilizing a ticket printer  222  to print tickets for a TITO system server  108 . Gaming device  200  may further include a bill validator  234 , player-input buttons  236  for player input, cabinet security sensors  238  to detect unauthorized opening of the cabinet  218 , a primary game display  240 , and a secondary game display  242 , each coupled to and operable under the control of game controller  202 . 
     The games available for play on the gaming device  200  are controlled by a game controller  202  that includes one or more processors  204 . Processor  204  represents a general-purpose processor, a specialized processor intended to perform certain functional tasks, or a combination thereof. As an example, processor  204  can be a central processing unit (CPU) that has one or more multi-core processing units and memory mediums (e.g., cache memory) that function as buffers and/or temporary storage for data. Alternatively, processor  204  can be a specialized processor, such as an application specific integrated circuit (ASIC), graphics processing unit (GPU), field-programmable gate array (FPGA), digital signal processor (DSP), or another type of hardware accelerator. In another example, processor  204  is a system on chip (SoC) that combines and integrates one or more general-purpose processors and/or one or more specialized processors. Although  FIG.  2 A  illustrates that game controller  202  includes a single processor  204 , game controller  202  is not limited to this representation and instead can include multiple processors  204  (e.g., two or more processors). 
       FIG.  2 A  illustrates that processor  204  is operatively coupled to memory  208 . Memory  208  is defined herein as including volatile and nonvolatile memory and other types of non-transitory data storage components. Volatile memory is memory that do not retain data values upon loss of power. Nonvolatile memory is memory that do retain data upon a loss of power. Examples of memory  208  include random access memory (RAM), read-only memory (ROM), hard disk drives, solid-state drives, universal serial bus (USB) flash drives, memory cards accessed via a memory card reader, floppy disks accessed via an associated floppy disk drive, optical discs accessed via an optical disc drive, magnetic tapes accessed via an appropriate tape drive, and/or other memory components, or a combination of any two or more of these memory components. In addition, examples of RAM include static random access memory (SRAM), dynamic random access memory (DRAM), magnetic random access memory (MRAM), and other such devices. Examples of ROM include a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or other like memory device. Even though  FIG.  2 A  illustrates that game controller  202  includes a single memory  208 , game controller  202  could include multiple memories  208  for storing program instructions and/or data. 
     Memory  208  can store one or more game programs  206  that provide program instructions and/or data for carrying out various implementations (e.g., game mechanics) described herein. Stated another way, game program  206  represents an executable program stored in any portion or component of memory  208 . In one or more implementations, game program  206  is embodied in the form of source code that includes human-readable statements written in a programming language or machine code that contains numerical instructions recognizable by a suitable execution system, such as a processor  204  in a game controller or other system. Examples of executable programs include: (1) a compiled program that can be translated into machine code in a format that can be loaded into a random access portion of memory  208  and run by processor  204 ; (2) source code that may be expressed in proper format such as object code that is capable of being loaded into a random access portion of memory  208  and executed by processor  204 ; and (3) source code that may be interpreted by another executable program to generate instructions in a random access portion of memory  208  to be executed by processor  204 . 
     Alternatively, game programs  206  can be set up to generate one or more game instances based on instructions and/or data that gaming device  200  exchanges with one or more remote gaming devices, such as a central determination gaming system server  106  (not shown in  FIG.  2 A  but shown in  FIG.  1   ). For purpose of this disclosure, the term “game instance” refers to a play or a round of a game that gaming device  200  presents (e.g., via a user interface (UI)) to a player. The game instance is communicated to gaming device  200  via the network  214  and then displayed on gaming device  200 . For example, gaming device  200  may execute game program  206  as video streaming software that allows the game to be displayed on gaming device  200 . When a game is stored on gaming device  200 , it may be loaded from memory  208  (e.g., from a read only memory (ROM)) or from the central determination gaming system server  106  to memory  208 . 
     Gaming devices, such as gaming device  200 , are highly regulated to ensure fairness and, in many cases, gaming device  200  is operable to award monetary awards (e.g., typically dispensed in the form of a redeemable voucher). Therefore, to satisfy security and regulatory requirements in a gaming environment, hardware and software architectures are implemented in gaming devices  200  that differ significantly from those of general-purpose computers. Adapting general purpose computers to function as gaming devices  200  is not simple or straightforward because of: (1) the regulatory requirements for gaming devices  200 , (2) the harsh environment in which gaming devices  200  operate, (3) security requirements, (4) fault tolerance requirements, and (5) the requirement for additional special purpose componentry enabling functionality of an EGM. These differences require substantial engineering effort with respect to game design implementation, game mechanics, hardware components, and software. 
     One regulatory requirement for games running on gaming device  200  generally involves complying with a certain level of randomness. Typically, gaming jurisdictions mandate that gaming devices  200  satisfy a minimum level of randomness without specifying how a gaming device  200  should achieve this level of randomness. To comply,  FIG.  2 A  illustrates that gaming device  200  could include an RNG  212  that utilizes hardware and/or software to generate RNG outcomes that lack any pattern. The RNG operations are often specialized and non-generic in order to comply with regulatory and gaming requirements. For example, in a slot game, game program  206  can initiate multiple RNG calls to RNG  212  to generate RNG outcomes, where each RNG call and RNG outcome corresponds to an outcome for a reel. In another example, gaming device  200  can be a Class II gaming device where RNG  212  generates RNG outcomes for creating Bingo cards. In one or more implementations, RNG  212  could be one of a set of RNGs operating on gaming device  200 . More generally, an output of the RNG  212  can be the basis on which game outcomes are determined by the game controller  202 . Game developers could vary the degree of true randomness for each RNG (e.g., pseudorandom) and utilize specific RNGs depending on game requirements. The output of the RNG  212  can include a random number or pseudorandom number (either is generally referred to as a “random number”). 
     In  FIG.  2 A , RNG  212  and hardware RNG  244  are shown in dashed lines to illustrate that RNG  212 , hardware RNG  244 , or both can be included in gaming device  200 . In one implementation, instead of including RNG  212 , gaming device  200  could include a hardware RNG  244  that generates RNG outcomes. Analogous to RNG  212 , hardware RNG  244  performs specialized and non-generic operations in order to comply with regulatory and gaming requirements. For example, because of regulation requirements, hardware RNG  244  could be a random number generator that securely produces random numbers for cryptography use. The gaming device  200  then uses the secure random numbers to generate game outcomes for one or more game features. In another implementation, the gaming device  200  could include both hardware RNG  244  and RNG  212 . RNG  212  may utilize the RNG outcomes from hardware RNG  244  as one of many sources of entropy for generating secure random numbers for the game features. 
     Another regulatory requirement for running games on gaming device  200  includes ensuring a certain level of RTP. Similar to the randomness requirement discussed above, numerous gaming jurisdictions also mandate that gaming device  200  provides a minimum level of RTP (e.g., RTP of at least 75%). A game can use one or more lookup tables (also called weighted tables) as part of a technical solution that satisfies regulatory requirements for randomness and RTP. In particular, a lookup table can integrate game features (e.g., trigger events for special modes or bonus games; newly introduced game elements such as extra reels, new symbols, or new cards; stop positions for dynamic game elements such as spinning reels, spinning wheels, or shifting reels; or card selections from a deck) with random numbers generated by one or more RNGs, so as to achieve a given level of volatility for a target level of RTP. (In general, volatility refers to the frequency or probability of an event such as a special mode, payout, etc. For example, for a target level of RTP, a higher-volatility game may have a lower payout most of the time with an occasional bonus having a very high payout, while a lower-volatility game has a steadier payout with more frequent bonuses of smaller amounts.) Configuring a lookup table can involve engineering decisions with respect to how RNG outcomes are mapped to game outcomes for a given game feature, while still satisfying regulatory requirements for RTP. Configuring a lookup table can also involve engineering decisions about whether different game features are combined in a given entry of the lookup table or split between different entries (for the respective game features), while still satisfying regulatory requirements for RTP and allowing for varying levels of game volatility. 
       FIG.  2 A  illustrates that gaming device  200  includes an RNG conversion engine  210  that translates the RNG outcome from RNG  212  to a game outcome presented to a player. To meet a designated RTP, a game developer can set up the RNG conversion engine  210  to utilize one or more lookup tables to translate the RNG outcome to a symbol element, stop position on a reel strip layout, and/or randomly chosen aspect of a game feature. As an example, the lookup tables can regulate a prize payout amount for each RNG outcome and how often the gaming device  200  pays out the prize payout amounts. The RNG conversion engine  210  could utilize one lookup table to map the RNG outcome to a game outcome displayed to a player and a second lookup table as a pay table for determining the prize payout amount for each game outcome. The mapping between the RNG outcome to the game outcome controls the frequency in hitting certain prize payout amounts. 
       FIG.  2 A  also depicts that gaming device  200  is connected over network  214  to player tracking system server  110 . Player tracking system server  110  may be, for example, an OASIS® system manufactured by Aristocrat® Technologies, Inc. Player tracking system server  110  is used to track play (e.g. amount wagered, games played, time of play and/or other quantitative or qualitative measures) for individual players so that an operator may reward players in a loyalty program. The player may use the player tracking interface  232  to access his/her account information, activate free play, and/or request various information. Player tracking or loyalty programs seek to reward players for their play and help build brand loyalty to the gaming establishment. The rewards typically correspond to the player&#39;s level of patronage (e.g., to the player&#39;s playing frequency and/or total amount of game plays at a given casino). Player tracking rewards may be complimentary and/or discounted meals, lodging, entertainment and/or additional play. Player tracking information may be combined with other information that is now readily obtainable by a casino management system. 
     When a player wishes to play the gaming device  200 , he/she can insert cash or a ticket voucher through a coin acceptor (not shown) or bill validator  234  to establish a credit balance on the gaming device. The credit balance is used by the player to place wagers on instances of the game and to receive credit awards based on the outcome of winning instances. The credit balance is decreased by the amount of each wager and increased upon a win. The player can add additional credits to the balance at any time. The player may also optionally insert a loyalty club card into the card reader  230 . During the game, the player views with one or more UIs, the game outcome on one or more of the primary game display  240  and secondary game display  242 . Other game and prize information may also be displayed. 
     For each game instance, a player may make selections, which may affect play of the game. For example, the player may vary the total amount wagered by selecting the amount bet per line and the number of lines played. In many games, the player is asked to initiate or select options during course of game play (such as spinning a wheel to begin a bonus round or select various items during a feature game). The player may make these selections using the player-input buttons  236 , the primary game display  240  which may be a touch screen, or using some other device which enables a player to input information into the gaming device  200 . 
     During certain game events, the gaming device  200  may display visual and auditory effects that can be perceived by the player. These effects add to the excitement of a game, which makes a player more likely to enjoy the playing experience. Auditory effects include various sounds that are projected by the speakers  220 . Visual effects include flashing lights, strobing lights or other patterns displayed from lights on the gaming device  200  or from lights behind the information panel  152  ( FIG.  1   ). 
     When the player is done, he/she cashes out the credit balance (typically by pressing a cash out button to receive a ticket from the ticket printer  222 ). The ticket may be “cashed-in” for money or inserted into another machine to establish a credit balance for play. 
     Additionally, or alternatively, gaming devices  104 A- 104 X and  200  can include or be coupled to one or more wireless transmitters, receivers, and/or transceivers (not shown in  FIGS.  1  and  2 A ) that communicate (e.g., Bluetooth® or other near-field communication technology) with one or more mobile devices to perform a variety of wireless operations in a casino environment. Examples of wireless operations in a casino environment include detecting the presence of mobile devices, performing credit, points, comps, or other marketing or hard currency transfers, establishing wagering sessions, and/or providing a personalized casino-based experience using a mobile application. In one implementation, to perform these wireless operations, a wireless transmitter or transceiver initiates a secure wireless connection between a gaming device  104 A- 104 X and  200  and a mobile device. After establishing a secure wireless connection between the gaming device  104 A- 104 X and  200  and the mobile device, the wireless transmitter or transceiver does not send and/or receive application data to and/or from the mobile device. Rather, the mobile device communicates with gaming devices  104 A- 104 X and  200  using another wireless connection (e.g., WiFi® or cellular network). In another implementation, a wireless transceiver establishes a secure connection to directly communicate with the mobile device. The mobile device and gaming device  104 A- 104 X and  200  sends and receives data utilizing the wireless transceiver instead of utilizing an external network. For example, the mobile device would perform digital wallet transactions by directly communicating with the wireless transceiver. In one or more implementations, a wireless transmitter could broadcast data received by one or more mobile devices without establishing a pairing connection with the mobile devices. 
     Although  FIGS.  1  and  2 A  illustrate specific implementations of a gaming device (e.g., gaming devices  104 A- 104 X and  200 ), the disclosure is not limited to those implementations shown in  FIGS.  1  and  2   . For example, not all gaming devices suitable for implementing implementations of the present disclosure necessarily include top wheels, top boxes, information panels, cashless ticket systems, and/or player tracking systems. Further, some suitable gaming devices have only a single game display that includes only a mechanical set of reels and/or a video display, while others are designed for bar counters or tabletops and have displays that face upwards. Gaming devices  104 A- 104 X and  200  may also include other processors that are not separately shown. Using  FIG.  2 A  as an example, gaming device  200  could include display controllers (not shown in  FIG.  2 A ) configured to receive video input signals or instructions to display images on game displays  240  and  242 . Alternatively, such display controllers may be integrated into the game controller  202 . The use and discussion of  FIGS.  1  and  2    are examples to facilitate ease of description and explanation. 
       FIG.  2 B  depicts a casino gaming environment according to one example. In this example, the casino  251  includes banks  252  of EGMs  104 . In this example, each bank  252  of EGMs  104  includes a corresponding gaming signage system  254  (also shown in  FIG.  2 A ). According to this implementation, the casino  251  also includes mobile gaming devices  256 , which are also configured to present wagering games in this example. The mobile gaming devices  256  may, for example, include tablet devices, cellular phones, smart phones and/or other handheld devices. In this example, the mobile gaming devices  256  are configured for communication with one or more other devices in the casino  251 , including but not limited to one or more of the server computers  102 , via wireless access points  258 . 
     According to some examples, the mobile gaming devices  256  may be configured for stand-alone determination of game outcomes. However, in some alternative implementations the mobile gaming devices  256  may be configured to receive game outcomes from another device, such as the central determination gaming system server  106 , one of the EGMs  104 , etc. 
     Some mobile gaming devices  256  may be configured to accept monetary credits from a credit or debit card, via a wireless interface (e.g., via a wireless payment app), via tickets, via a patron casino account, etc. However, some mobile gaming devices  256  may not be configured to accept monetary credits via a credit or debit card. Some mobile gaming devices  256  may include a ticket reader and/or a ticket printer whereas some mobile gaming devices  256  may not, depending on the particular implementation. 
     In some implementations, the casino  251  may include one or more kiosks  260  that are configured to facilitate monetary transactions involving the mobile gaming devices  256 , which may include cash out and/or cash in transactions. The kiosks  260  may be configured for wired and/or wireless communication with the mobile gaming devices  256 . The kiosks  260  may be configured to accept monetary credits from casino patrons  262  and/or to dispense monetary credits to casino patrons  262  via cash, a credit or debit card, via a wireless interface (e.g., via a wireless payment app), via tickets, etc. According to some examples, the kiosks  260  may be configured to accept monetary credits from a casino patron and to provide a corresponding amount of monetary credits to a mobile gaming device  256  for wagering purposes, e.g., via a wireless link such as a near-field communications link. In some such examples, when a casino patron  262  is ready to cash out, the casino patron  262  may select a cash out option provided by a mobile gaming device  256 , which may include a real button or a virtual button (e.g., a button provided via a graphical user interface) in some instances. In some such examples, the mobile gaming device  256  may send a “cash out” signal to a kiosk  260  via a wireless link in response to receiving a “cash out” indication from a casino patron. The kiosk  260  may provide monetary credits to the casino patron  262  corresponding to the “cash out” signal, which may be in the form of cash, a credit ticket, a credit transmitted to a financial account corresponding to the casino patron, etc. 
     In some implementations, a cash-in process and/or a cash-out process may be facilitated by the TITO system server  108 . For example, the TITO system server  108  may control, or at least authorize, ticket-in and ticket-out transactions that involve a mobile gaming device  256  and/or a kiosk  260 . 
     Some mobile gaming devices  256  may be configured for receiving and/or transmitting player loyalty information. For example, some mobile gaming devices  256  may be configured for wireless communication with the player tracking system server  110 . Some mobile gaming devices  256  may be configured for receiving and/or transmitting player loyalty information via wireless communication with a patron&#39;s player loyalty card, a patron&#39;s smartphone, etc. 
     According to some implementations, a mobile gaming device  256  may be configured to provide safeguards that prevent the mobile gaming device  256  from being used by an unauthorized person. For example, some mobile gaming devices  256  may include one or more biometric sensors and may be configured to receive input via the biometric sensor(s) to verify the identity of an authorized patron. Some mobile gaming devices  256  may be configured to function only within a predetermined or configurable area, such as a casino gaming area. 
       FIG.  2 C  is a diagram that shows examples of components of a system for providing online gaming according to some aspects of the present disclosure. As with other figures presented in this disclosure, the numbers, types and arrangements of gaming devices shown in  FIG.  2 C  are merely shown by way of example. In this example, various gaming devices, including but not limited to end user devices (EUDs)  264   a ,  264   b  and  264   c  are capable of communication via one or more networks  417 . The networks  417  may, for example, include one or more cellular telephone networks, the Internet, etc. In this example, the EUDs  264   a  and  264   b  are mobile devices: according to this example the EUD  264   a  is a tablet device and the EUD  264   b  is a smart phone. In this implementation, the EUD  264   c  is a laptop computer that is located within a residence  266  at the time depicted in  FIG.  2 C . Accordingly, in this example the hardware of EUDs is not specifically configured for online gaming, although each EUD is configured with software for online gaming. For example, each EUD may be configured with a web browser. Other implementations may include other types of EUD, some of which may be specifically configured for online gaming. 
     In this example, a gaming data center  276  includes various devices that are configured to provide online wagering games via the networks  417 . The gaming data center  276  is capable of communication with the networks  417  via the gateway  272 . In this example, switches  278  and routers  280  are configured to provide network connectivity for devices of the gaming data center  276 , including storage devices  282   a , servers  284   a  and one or more workstations  570   a . The servers  284   a  may, for example, be configured to provide access to a library of games for online game play. In some examples, code for executing at least some of the games may initially be stored on one or more of the storage devices  282   a . The code may be subsequently loaded onto a server  284   a  after selection by a player via an EUD and communication of that selection from the EUD via the networks  417 . The server  284   a  onto which code for the selected game has been loaded may provide the game according to selections made by a player and indicated via the player&#39;s EUD. In other examples, code for executing at least some of the games may initially be stored on one or more of the servers  284   a . Although only one gaming data center  276  is shown in  FIG.  2 C , some implementations may include multiple gaming data centers  276 . 
     In this example, a financial institution data center  270  is also configured for communication via the networks  417 . Here, the financial institution data center  270  includes servers  284   b , storage devices  282   b , and one or more workstations  286   b . According to this example, the financial institution data center  270  is configured to maintain financial accounts, such as checking accounts, savings accounts, loan accounts, etc. In some implementations one or more of the authorized users  274   a - 274   c  may maintain at least one financial account with the financial institution that is serviced via the financial institution data center  270 . 
     According to some implementations, the gaming data center  276  may be configured to provide online wagering games in which money may be won or lost. According to some such implementations, one or more of the servers  284   a  may be configured to monitor player credit balances, which may be expressed in game credits, in currency units, or in any other appropriate manner. In some implementations, the server(s)  284   a  may be configured to obtain financial credits from and/or provide financial credits to one or more financial institutions, according to a player&#39;s “cash in” selections, wagering game results and a player&#39;s “cash out” instructions. According to some such implementations, the server(s)  284   a  may be configured to electronically credit or debit the account of a player that is maintained by a financial institution, e.g., an account that is maintained via the financial institution data center  270 . The server(s)  284   a  may, in some examples, be configured to maintain an audit record of such transactions. 
     In some alternative implementations, the gaming data center  276  may be configured to provide online wagering games for which credits may not be exchanged for cash or the equivalent. In some such examples, players may purchase game credits for online game play, but may not “cash out” for monetary credit after a gaming session. Moreover, although the financial institution data center  270  and the gaming data center  276  include their own servers and storage devices in this example, in some examples the financial institution data center  270  and/or the gaming data center  276  may use offsite “cloud-based” servers and/or storage devices. In some alternative examples, the financial institution data center  270  and/or the gaming data center  276  may rely entirely on cloud-based servers. 
     One or more types of devices in the gaming data center  276  (or elsewhere) may be capable of executing middleware, e.g., for data management and/or device communication. Authentication information, player tracking information, etc., including but not limited to information obtained by EUDs  264  and/or other information regarding authorized users of EUDs  264  (including but not limited to the authorized users  274   a - 274   c ), may be stored on storage devices  282  and/or servers  284 . Other game-related information and/or software, such as information and/or software relating to leaderboards, players currently playing a game, game themes, game-related promotions, game competitions, etc., also may be stored on storage devices  282  and/or servers  284 . In some implementations, some such game-related software may be available as “apps” and may be downloadable (e.g., from the gaming data center  276 ) by authorized users. 
     In some examples, authorized users and/or entities (such as representatives of gaming regulatory authorities) may obtain gaming-related information via the gaming data center  276 . One or more other devices (such EUDs  264  or devices of the gaming data center  276 ) may act as intermediaries for such data feeds. Such devices may, for example, be capable of applying data filtering algorithms, executing data summary and/or analysis software, etc. In some implementations, data filtering, summary and/or analysis software may be available as “apps” and downloadable by authorized users. 
       FIG.  3    illustrates, in block diagram form, an implementation of a game processing architecture  300  that implements a game processing pipeline for the play of a game in accordance with various implementations described herein. As shown in  FIG.  3   , the gaming processing pipeline starts with having a UI system  302  receive one or more player inputs for the game instance. Based on the player input(s), the UI system  302  generates and sends one or more RNG calls to a game processing backend system  314 . Game processing backend system  314  then processes the RNG calls with RNG engine  316  to generate one or more RNG outcomes. The RNG outcomes are then sent to the RNG conversion engine  320  to generate one or more game outcomes for the UI system  302  to display to a player. The game processing architecture  300  can implement the game processing pipeline using a gaming device, such as gaming devices  104 A- 104 X and  200  shown in  FIGS.  1  and  2   , respectively. Alternatively, portions of the gaming processing architecture  300  can implement the game processing pipeline using a gaming device and one or more remote gaming devices, such as central determination gaming system server  106  shown in  FIG.  1   . 
     The UI system  302  includes one or more UIs that a player can interact with. The UI system  302  could include one or more game play UIs  304 , one or more bonus game play UIs  308 , and one or more multiplayer UIs  312 , where each UI type includes one or more mechanical UIs and/or graphical UIs (GUIs). In other words, game play UI  304 , bonus game play UI  308 , and the multiplayer UI  312  may utilize a variety of UI elements, such as mechanical UI elements (e.g., physical “spin” button or mechanical reels) and/or GUI elements (e.g., virtual reels shown on a video display or a virtual button deck) to receive player inputs and/or present game play to a player. Using  FIG.  3    as an example, the different UI elements are shown as game play UI elements  306 A- 306 N and bonus game play UI elements  310 A- 310 N. 
     The game play UI  304  represents a UI that a player typically interfaces with for a base game. During a game instance of a base game, the game play UI elements  306 A- 306 N (e.g., GUI elements depicting one or more virtual reels) are shown and/or made available to a user. In a subsequent game instance, the UI system  302  could transition out of the base game to one or more bonus games. The bonus game play UI  308  represents a UI that utilizes bonus game play UI elements  310 A- 310 N for a player to interact with and/or view during a bonus game. In one or more implementations, at least some of the game play UI element  306 A- 306 N are similar to the bonus game play UI elements  310 A- 310 N. In other implementations, the game play UI element  306 A- 306 N can differ from the bonus game play UI elements  310 A- 310 N. 
       FIG.  3    also illustrates that UI system  302  could include a multiplayer UI  312  purposed for game play that differs or is separate from the typical base game. For example, multiplayer UI  312  could be set up to receive player inputs and/or presents game play information relating to a tournament mode. When a gaming device transitions from a primary game mode that presents the base game to a tournament mode, a single gaming device is linked and synchronized to other gaming devices to generate a tournament outcome. For example, multiple RNG engines  316  corresponding to each gaming device could be collectively linked to determine a tournament outcome. To enhance a player&#39;s gaming experience, tournament mode can modify and synchronize sound, music, reel spin speed, and/or other operations of the gaming devices according to the tournament game play. After tournament game play ends, operators can switch back the gaming device from tournament mode to a primary game mode to present the base game. Although  FIG.  3    does not explicitly depict that multiplayer UI  312  includes UI elements, multiplayer UI  312  could also include one or more multiplayer UI elements. 
     Based on the player inputs, the UI system  302  could generate RNG calls to a game processing backend system  314 . As an example, the UI system  302  could use one or more application programming interfaces (APIs) to generate the RNG calls. To process the RNG calls, the RNG engine  316  could utilize gaming RNG  318  and/or non-gaming RNGs  319 A- 319 N. Gaming RNG  318  could corresponds to RNG  212  or hardware RNG  244  shown in  FIG.  2 A . As previously discussed with reference to  FIG.  2 A , gaming RNG  318  often performs specialized and non-generic operations that comply with regulatory and/or game requirements. For example, because of regulation requirements, gaming RNG  318  could correspond to RNG  212  by being a cryptographic RNG or pseudorandom number generator (PRNG) (e.g., Fortuna PRNG) that securely produces random numbers for one or more game features. To securely generate random numbers, gaming RNG  318  could collect random data from various sources of entropy, such as from an operating system (OS) and/or a hardware RNG (e.g., hardware RNG  244  shown in  FIG.  2 A ). Alternatively, non-gaming RNGs  319 A- 319 N may not be cryptographically secure and/or be computationally less expensive. Non-gaming RNGs  319 A- 319 N can, thus, be used to generate outcomes for non-gaming purposes. As an example, non-gaming RNGs  319 A- 319 N can generate random numbers for generating random messages that appear on the gaming device. 
     The RNG conversion engine  320  processes each RNG outcome from RNG engine  316  and converts the RNG outcome to a UI outcome that is feedback to the UI system  302 . With reference to  FIG.  2 A , RNG conversion engine  320  corresponds to RNG conversion engine  210  used for game play. As previously described, RNG conversion engine  320  translates the RNG outcome from the RNG  212  to a game outcome presented to a player. RNG conversion engine  320  utilizes one or more lookup tables  322 A- 322 N to regulate a prize payout amount for each RNG outcome and how often the gaming device pays out the derived prize payout amounts. In one example, the RNG conversion engine  320  could utilize one lookup table to map the RNG outcome to a game outcome displayed to a player and a second lookup table as a pay table for determining the prize payout amount for each game outcome. In this example, the mapping between the RNG outcome and the game outcome controls the frequency in hitting certain prize payout amounts. Different lookup tables could be utilized depending on the different game modes, for example, a base game versus a bonus game. 
     After generating the UI outcome, the game processing backend system  314  sends the UI outcome to the UI system  302 . Examples of UI outcomes are symbols to display on a video reel or reel stops for a mechanical reel. In one example, if the UI outcome is for a base game, the UI system  302  updates one or more game play UI elements  306 A- 306 N, such as symbols, for the game play UI  304 . In another example, if the UI outcome is for a bonus game, the UI system could update one or more bonus game play UI elements  310 A- 310 N (e.g., symbols) for the bonus game play UI  308 . In response to updating the appropriate UI, the player may subsequently provide additional player inputs to initiate a subsequent game instance that progresses through the game processing pipeline. 
     The present disclosure describes various implementations in which a main game, e.g., as may be provided by game processing architecture  300  of  FIG.  3   , is configured to include an array growth feature that allows an array of symbol positions used to display symbols as part of a graphical game play UI  304 , e.g., such as by UI system  302  of  FIG.  3   , during game play of the main game to be increased in size in one dimension during game play responsive to satisfaction of an array growth condition. In such implementations, the main game is also configured to cause a feature game, such as may be presented via a bonus game UI  308 , to be presented responsive to a feature game trigger condition being met—the feature game that is presented uses an array of symbol positions that has first and second dimensions that are the same as the first and second dimensions of the array of symbol positions in use in the main game at the time the feature game trigger condition was met. Such configurations are able to maintain player interest, and thus potential revenue streams resulting from game play, more effectively since a player that is playing the main game while the main game is displaying an increased-size array of symbol positions is will likely wish to continue playing knowing that a) their chances of triggering the feature game are likely increased due to the larger array size and b) that their chances of achieving a higher reward from the feature game, should it be triggered, will also be increased due to the increased array size. Moreover, such implementations may also allow for additional array growth during the feature game as well, thus building further on array growth that may occur during play of the main game. 
     The main games and feature games that are discussed below may both be described as being symbol-based games in which symbols are selected for display, e.g., randomly selected, such as via RNG engine  316  of  FIG.  3   , in an array of symbol positions presented to a player via a GUI as part of each play of the relevant game. Each symbol position is thus caused to display a corresponding symbol for each instance of game play. The arrays in question are typically rectangular arrays and may have a first dimension and a second dimension; the dimensions of an array refer to the number of elements the array has along two different, usually orthogonal, directions. For example, in a 3×5 slot machine game, the symbols that are displayed are shown in an array of symbol positions with five symbol positions in the horizontal direction and three symbol positions in the vertical direction. It will be understood that the techniques discussed below may be implemented in symbol-based games having arrays of symbol positions of any dimension, including 3×3, 3×4, 4×3, 4×5, 5×5, 4×6, 5×6, etc. In the presently described symbol-based games, the second dimension of the array may be modified during game play so as to add an additional set of symbol positions, equal in number to the first dimension of the array of symbol positions, to the array of symbol positions such that the size of the array in one direction increases, e.g., such that the second dimension of the array increases by one. 
     Many such symbol-based games may be considered to be reel strip games in which the symbols that are shown in parallel linear arrays of symbol positions within the larger array of symbol positions are selected so that the symbols that are depicted in each linear array are identical to, and in the same order as, a sequentially adjacent set of symbols within an ordered set of symbols associated with that linear array; sequentially adjacent, in this context, refers to items that are directly adjacent to each other in a sequence, i.e., with no other items in between them. For example, in mechanical slot machine games, the symbols that were displayed in the various symbol positions were provided by rotating a reel that had a collection of symbols positioned at various locations along its outer circumference. Only the symbols that were located on the portion of the reel that was visible to the player at any given time were shown to the player, and the symbols on the reel were always shown in the same sequence with each revolution of the reel. In most such mechanical slot machine games, the symbols were printed on a flexible reel strip that was wrapped around the outer circumference of the reel, thereby allowing the reel strips to be changed out if desired. The reel strips were generally strips of material having a length and width approximately equal to the circumference and width, respectively, of the reel; the symbols were then printed on this material, e.g., using silk screening or other suitable process, in the sequence in which they were to appear when the reel was spun. In digital slot machines, the physical reels are typically replaced with virtual representations thereof, and each reel strip correspondingly replaced with a “virtual” reel strip that includes information indicating an ordered sequence of symbols, e.g., information defining the sequential position of each symbol and what that symbol is, e.g., information identifying graphical content representing the symbol. 
     In virtual versions of reel strips, the symbols that represent a virtual reel strip may be associated with information that allows a sequence for such symbols to be determined. Such sequences may be cyclic, e.g., the first symbol in the sequence may be viewed as sequentially adjacent not only to the second symbol in the sequence, but also to the last. Similarly, the last symbol in the sequence may be viewed as sequentially adjacent to the first symbol in the sequence as well as to the penultimate symbol in the sequence. 
     It will be understood that reference herein to “selecting a symbol” is inclusive not only of directly selecting, for example, a specific image file of a symbol, but also of indirectly selecting graphical content to be displayed for a particular symbol. For example, “selecting a symbol” may include selecting an item from a sequential list of items in which each item includes information that allows graphical content for a particular symbol to be obtained and displayed but does not, itself, directly contain the graphical content. For example, a virtual reel strip may be an array that stores unique serial numbers, file names, or other identifiers that identify particular graphical assets that are each associated with a particular array position (thus defining a sequential order therefore) then retrieved and displayed to a user to show the relevant graphical content. In some implementations of digital symbol-based games that use virtual reel strips, symbols may be selected and displayed in each parallel linear array of symbol positions from such reel strips in contiguous blocks so as to simulate how a physical reel would provide symbols for display. In some other implementations, however, the symbol selected for display in each reel position may be made randomly. In most symbol-based games in which an array growth feature is implemented, the second dimension of the array of symbol positions may be along the axis perpendicular to the linear arrays discussed above. For example, if a 3×5 array of symbol positions supporting array growth includes 5 columns and 3 rows of symbol positions, with each column associated with a different reel strip, the second dimension would be the number of rows (3) and the first dimension would be the number of columns (5). It will be recognized that in most such implementations, the second dimension will correspond with the number of rows in the array, but it will also be apparent that the second dimension may, in some cases, instead correspond with the number of columns in the array. For example, for a slot-type symbol-based game that uses virtual reels that rotate about a vertical axis (instead of horizontal, as is usually the case for slot-type games), the second dimension may govern the number of columns of symbol positions that are used as opposed to the number of rows of symbol positions that are used. 
     Various specific implementations of games having symbol position arrays with a persistent growth feature are discussed below in more detail. 
       FIG.  4    depicts a flow chart of main game play for a main game featuring persistent array growth for an array of symbol positions. In block  402 , an array of symbol positions may be identified; each symbol position may be associated with location information that may govern where a symbol associated with that symbol position is to be displayed on a display or displays of an electronic gaming machine. The array of symbol positions may have a first dimension and a second dimension. When the main game is first played, e.g., after starting up the main game, the array of symbol positions may be set to a default value. The default value, in many implementations, will typically correspond to a minimum size of the array of symbol positions that may be allowed to occur within the main game during game play. 
     In block  404 , an input may be received that indicates a game play of the main game. For example, such an input may correspond with an electrical signal that arises from a physical “play” or “spin” button being pressed by a user on an electronic gaming machine, or from a virtual analog of such buttons provided on a touch screen. Receipt of such an input by the electronic gaming machine may cause the electronic gaming machine to initiate a play of the main game. This may include, for example, selecting symbols in block  406  that are to be displayed in each symbol position of the array of symbol positions. It may also include initiating various animations or sound effects that are intended to symbolically or figuratively represent the symbol selection process, e.g., animations of spinning reels may be displayed, as well as sound effects associated therewith. 
     The symbol selection that occurs in block  406  may, in many implementations, be random. In some implementations, such random selection may be from a single, large set of symbols. In other implementations, there may be a set of symbols (which may include multiple instances of one or more of the symbols) associated with the main game that may be subdivided into multiple subsets of symbols, with each subset of symbols associated with a different set of symbol positions in the array that all have the same index value for the first dimension of the array. For example, each set of symbol positions for an example main game may correspond with a different column of symbol positions in which symbols selected from a corresponding virtual reel strip are displayed; the corresponding virtual reel strip for each set of symbol positions may represent the subset of symbols for that set of symbol positions. The set of symbols for a given game play in such an example would include all of the symbols included on all of the virtual reel strips from which symbols are selected for that game play. 
     It will also be understood that symbol selection for a given game play may also optionally involve selecting between different sets of symbols before selecting symbols for display in the symbol positions from the selected set of symbols. In such implementations, each set of symbols may, similar to the example discussed above, have corresponding subsets of symbols from which symbols may be selected for different sets of symbol positions. For example, a main game may have various special features that may be activated when a particular triggering symbol is displayed as a result of play of the main game. It may, however, be desirable to only potentially trigger one of these special features for any given play of the main game. For example, the main game may have a “free spin(s)” feature in which the player is allowed to engage in some predetermined number of free game plays, e.g., without needing to place a wager using their own funds, an “array growth” feature (as discussed above and also below in more detail), and a “feature game” feature, e.g., a bonus game that may be presented to the player and which may have game play that differs from the main game in some way. It may be desirable to avoid scenarios in which a player might trigger two of more of these features simultaneously, e.g., doing so may confuse the player, or the player may assume that the features will be activated in a particular order that is different from the order used by the electronic gaming machine (for example, if both the free spin(s) feature and the array growth feature are triggered, are the free spins provided after the array growth occurs or before?). To avoid such scenarios, it may be desirable to have three sets of symbols—one with one or more free spin symbols but no feature game trigger symbols or array growth symbols, one with one or more array growth symbols but not feature game trigger symbols or free spin symbols, and one with one or more feature game trigger symbols but no array growth symbols or free spin symbols. In such an implementation, a selection may be made between two or more of such sets of symbols before symbols for display are actually selected from the selected set of symbols. 
     Each set may, of course, include other symbols as well, e.g., symbols that are used to evaluate whether one or more winning patterns of symbols are displayed along one or more paylines associated with the main game and which may not be associated with a feature such as the above-discussed features. Paylines typically include a sequence of symbols, with each symbol in the sequence taken from the symbols being displayed for a different set of symbol positions, where each set of symbol positions includes symbol positions that share an array index in common with each other. For example, in many slot-type main games in which each vertical column of symbol positions displays symbols selected from a virtual reel, each payline may include one symbol from each column of symbols displayed. If the symbols associated with a particular payline form a pattern that matches a pattern that is specified as being associated with a winning outcome, the player that obtained such a pattern may be awarded an award of credits (either credits redeemable for currency or non-redeemable credits, e.g., social gaming currency) or other prize. 
     In some symbol-based games, such paylines may be limited in number, e.g., in a 3×5 symbol-based game, there may be three paylines that cover, collectively, the top, bottom, and middle rows of 5 symbols displayed. Other such symbol-based games may include additional paylines, e.g., diagonal paylines, W-shaped or M-shaped paylines, etc. Some symbol-based games, however, may allow for winning patterns along all paylines that exist under certain constraints. These games may be referred to as “ways” games, and may evaluate symbol patterns along all paylines that can be established within the array of symbol positions subject to certain constraints. For example, a typical ways game will evaluate symbol patterns that arise on all paylines that include one symbol from each set of symbol positions, with each set of symbol positions representing a different column of symbol positions within the array and with the symbols arranged in order of left-to-right appearance within the array. Thus, for example, a ways game with a 3×5 array of symbol positions (3 rows, 5 columns) would have 3 5 =243 paylines along which winning patterns may be determined. A ways game with a 4×5 array of symbol positions would similarly have 1024 paylines, a 5×5 array of symbol positions would have 3125 paylines, and a 6×5 array of symbol positions would have 7776 paylines. 
     In block  408 , the symbols selected for display in each of the symbol positions may be caused to be displayed on the display in locations associated with the corresponding symbol positions. It will be understood that such display is inclusive of examples in which one or more symbols that were displayed in a location or locations on the display or displays associated with one or more corresponding symbol positions do not change, e.g., there may be some main games in which a certain type of displayed symbol may, once displayed, be caused to remain in place for one or more subsequent game plays (often referred to as a “sticky” symbol). In such a case, the “sticky” symbol may simply be retained for display in that symbol position for as long as the symbol remains “sticky”—this, in itself, may be viewed as a form of symbol selection (thus, the later displays/continued display of sticky symbols may be considered to be a non-random selection of that symbol for display—although the sticky symbol may have been randomly selected for display initially). 
     In block  410 , symbols displayed in the array of symbol positions that are array growth symbols may be identified; in some instances, such identification may simply amount to determining how many of such array growth symbols are displayed within the array of symbol positions. Such identification may also be performed prior to display of the symbols but after selection of the symbols. 
     In block  412 , a determination is made as to whether the displayed array growth symbol(s), if any, meet an array growth condition. The array growth condition may, for example, be any one or more conditions that, if satisfied, may cause block  414  to be performed so as to cause the electronic gaming machine to increase the size of the array of symbol positions by increasing the second dimension of the array by one or more units. For example, satisfaction of an array growth condition may cause the electronic gaming machine to cause the array of symbol positions to expand by one row if the second dimension indicates the number of rows in the array. Other implementations may involve causing the second dimension of the array of symbol positions to increase by more than one unit in size, e.g., two units or three units, responsive to the array growth condition being met. In block  416 , symbols may be selected and displayed for any symbol positions newly added to the array of symbol positions in block  414 . Such newly added symbols may be selected responsive to a determination that the second dimension of the array of symbol positions should be increased or may, alternatively, have been selected as part of the original selection of symbols in block  406  but not included in the symbols that were displayed in block  408 . For example, if the electronic gaming machine is configured to present a 3×5 array of symbol positions that can be grown to a maximum of a 6×5 array through the above-described array growth mechanism, block  406  may not only include selecting symbols for the symbol positions in the array of symbol positions based on its dimensions at the time of the game play, but may also include selecting symbols for symbol positions that are not part of the array of symbol positions at the time of game play but could be if an array growth condition were to be met in that game play. 
     Various array growth conditions may be used, although perhaps the simplest and most common is an array growth condition that is satisfied when at least one displayed, or to-be-displayed, symbol is an array growth symbol. A somewhat more restrictive array growth condition may require that a plurality of displayed or to-be-displayed symbols for a given game play be array growth symbols. It will be understood that “displayed” symbols are inclusive of both symbols that are actually displayed for the game play in question or that have been selected for display for that given game play but have not yet actually been displayed in association with that game play. Other examples of array growth conditions may include, for example, conditions that are met when an array growth symbol is displayed in a particular location in the array of symbol positions, e.g., in a symbol position along a top edge of the array, or conditions that are met when a specified set of array growth symbols are displayed. For example, there may be several types of array growth symbols that are able to be selected, e.g., one that shows a small flower, one that shows a watering can, and one that shows the sun—the array growth condition may require that at least one array growth symbol of each of the three such types of array growth symbols be displayed for a given game play in order to be satisfied (in this case, the three symbols are selected so as to represent items needed to grow a flower, much as the array is grown, but such thematic linkage is not necessary). Some array growth conditions may be variable, e.g., the number of array growth symbols that must be displayed as the result of a play of the game in order to satisfy the array growth condition may increase based on the size of the array. For example, at least one array growth symbol may need to be displayed to cause the second dimension of the array to increase by one unit from its base value, but at least two array growth symbols may need to be displayed to then cause the second dimension of the array to grow by a further one unit (e.g., the base value plus two), and at least three array growth symbols may need to be displayed to cause the second dimension of the array to grow by a further one unit beyond that (e.g., the base value plus three). Array growth conditions may also optionally include requirements that may be independent of the number of array growth symbols that are shown. For example, an array growth condition may require, in addition to a predetermined number of array growth symbols being shown, that the second dimension of the array be less than the maximum permitted value for the array. 
     In some implementations, if the array growth symbols that are displayed for a given game play are sufficient to satisfy the array growth condition multiple times, then the electronic gaming machine may cause the second array dimension to correspondingly increase multiple times. For example, if the array growth condition is that an array growth symbol must be displayed and a game play results in two array growth symbols being displayed, the array growth feature may be triggered twice for that game play, resulting in twice as much array growth as would be the case if a single such array growth symbol were to be displayed for that game play. In other implementations, however, only one array growth operation may be performed for any given game play responsive to the array growth condition being met as a result of that game play, even if the array growth condition is met multiple times. 
     It will be understood that in most implementations, the electronic gaming machine may be configured to only permit a limited degree of dimensional growth in the array of symbol positions. For example, the electronic gaming machine may only allow a maximum of 2, 3, 4, 5, 6, or 7 units in total to be added to the second dimension. Such limitation may be accomplished in any feasible manner, including, but not limited to, ceasing use of a set of symbols that includes the array growth symbols, ignoring any array growth symbols that might be selected (not displaying them), etc. 
     After completion of block  416 , the technique may proceed to block  418 , which is the same block that the technique may proceed to if it is determined in block  412  that the array growth symbols displayed for that game play, if any, do not meet the array growth condition. 
     In block  418 , a determination may be made as to any win amounts, e.g., based on symbol patterns along paylines, as discussed above, that may have resulted from the game play. If the game play has resulted, for example, in any winning combination of symbols to be displayed along any of the paylines for the symbol-based game, the electronic gaming machine may cause a credit balance, score, or other metric to be incremented by the amount of the win. A notification may be provided to the player to indicate the amount of the win. 
     In block  420 , any displayed symbols that are feature game trigger symbols may be identified. The feature game trigger symbols may be all of the same type or may be multiple different types. For example, in some implementations, the feature game trigger symbols may be cash-on-reel symbols that may display different numeric amounts of credit or point values and/or different levels of jackpot awards, e.g., major, mini, minor. These may all be treated as “feature game trigger symbols” despite having different appearances and potentially being treated differently in contexts other than in feature game triggering (for example, the feature game trigger symbols may also be used to determine award amounts in some contexts, and the different types of feature game trigger symbols may have different effects on the award amount that is determined). In block  422 , a determination may be made as to whether the feature game trigger symbols identified in block  420  meet a feature game trigger condition. If not, the technique may return to block  404 , where a further input may be received indicative of another game play (assuming the player elects to continue playing). In the event that a determination is made that the feature game trigger condition is met, the technique may proceed to block  424 , in which a feature game may be provided for play. The technique may then proceed to return to block  404  after the feature game concludes. 
     As with the array growth condition, the feature game trigger condition may, depending on the implementation, take any of several forms. For example, the feature game trigger condition may be met when a predetermined number of feature game trigger symbols are displayed in the array of symbol positions. In some implementations, the minimum number of the feature game trigger symbols that must be displayed to meet the feature game trigger condition may be equal to the maximum value that the second array dimension is allowed to reach as a result of the array growth feature being triggered. For example, an electronic gaming machine may be configured to allow a 3×5 array of symbol positions may be “grown” to be as large as a 6×5 array of symbol positions but may prevent further growth beyond that level. In some such implementations, the electronic gaming machine may be further configured to have a feature game trigger condition that is met when six feature game trigger symbols are displayed in the array of symbol positions. 
     By increasing the size of the symbol position array, electronic gaming machines providing such main games may present players with an increased chance of earning an opportunity to play a feature game since the additional symbol positions that are added when the array size is grown responsive to the array growth trigger condition being met provide additional opportunities for a) additional array growth symbols to be shown and b) additional feature game trigger symbols to be shown, both of which may contribute to meeting respective array growth conditions and feature game trigger conditions. 
       FIG.  5    depicts a flow chart of feature game play for a feature game that uses an array of symbol positions inherited from a main game having persistent array growth for an array of symbol positions. In some implementations, the feature game trigger symbols may be replaced by different feature game symbols, whereas in other implementations, the same symbols may be used as both the feature game trigger symbols and the feature game symbols, e.g., such symbols may have a dual purpose/use. 
     If a feature game is trigged as a result of the determination in block  422 , the presentation of the feature game may begin in block  502 , in which the feature game may be initialized using an array of symbol positions from the main game that is inclusive of any array growth that may have occurred in the main game. In some implementations, the symbols displayed in each symbol position of the array of symbol positions in the feature game may be the same symbols shown in the array of symbol positions in the main game at the time the feature game is triggered. In such implementations, the feature game may, in some instances, use the same array of symbol positions and displayed symbols that were most recently provided in the main game when initiating the feature game. 
     In block  504 , an input may be received that is indicative of a game play of the feature game. Such an input may, similar to the input received in block  404 , be an input signal that is indicative of a player interaction with the electronic gaming machine that indicates that the player wishes to engage in a play of the feature game. 
     In block  506 , symbols may be selected for each symbol position that does not already have a feature game symbol displayed (symbols may also be selected for the symbol positions that have the feature game symbol displayed, but those symbols may be ignored/not displayed in those symbol positions). Such symbol selection may occur randomly, similar to the selection methods discussed above with respect to block  406 . 
     In block  508 , the selected symbols from block  506  may be caused to be displayed in the corresponding symbol positions in the array of symbol positions that do not already have feature game symbols displayed. 
     In block  510 , symbols displayed in the array of symbol positions that are array growth symbols may be identified; as in block  410 , such identification may simply amount to, in some instances, determining how many of such array growth symbols are displayed within the array of symbol positions. Such identification may also be performed prior to display of the symbols but after selection of the symbols. 
     In block  512 , a determination may be made, similar to that in block  412 , as to whether the displayed array growth symbol(s), if any, meet the array growth condition. The array growth condition may, as discussed earlier, be any one or more conditions that, if satisfied, may cause block  514  to be performed so as to cause the electronic gaming machine to increase the size of the array of symbol positions by increasing the second dimension of the array by one or more units. In block  516 , symbols may be selected and displayed for any symbol positions newly added to the array of symbol positions in block  514 , similar to the operations performed in block  416 . 
     Following block  516 , or block  512  should it be determined in block  512  that the array growth condition is not met as a result of the current game play of the feature game, the technique may proceed to block  518 , in which any newly displayed symbols that are also feature game symbols may be identified. In block  520 , a determination may be made as to whether any of the newly displayed feature game symbols meet a remaining play counter reset condition. For example, in feature games that are often referred to as “hold and spin” games, players are typically provided with a set number of spins or plays of the feature game. The remaining play counter may be decremented by one for each spin or play of the feature game until the player runs out of plays, at which point the feature game may be concluded and game play may return to the main game. When a feature game symbol is caused to be displayed in a symbol position such that it replaces a symbol other than a feature game symbol, the newly displayed feature game symbols may be evaluated in block  520  to see if they meet the requirements of a remaining play counter reset condition. If the remaining play counter reset condition is not met, then the technique may proceed to block  522 , in which the remaining play counter may be decremented by one unit to reflect that a play of the feature game has occurred. The technique may then proceed to block  524  in which a determination is made if the remaining spin counter has zero units remaining. If it is determined in block  520  that the remaining play counter reset condition is met, then the technique may instead proceed to block  526 , in which zero or more units may be added to the remaining play counter. In some implementations, the amount that may be added to the remaining play counter may be equal to the difference between the current value of the remaining play counter and the initial value of the remaining play counter at the start of the feature game, i.e., the remaining play counter may be reset to its initial value. 
     The remaining play counter reset condition may be any one of a variety of conditions, depending on the implementation. For example, in some implementations, any feature game symbol that is newly displayed as a result of a feature game play may satisfy the remaining play counter reset condition. In some such implementations, the reset that occurs to the remaining play counter may be a complete reset, i.e., it may be restored to its initial value. In other implementations, the reset that occurs to the remaining play counter when the remaining play counter reset condition is met may be a partial reset, e.g., adding 1 unit to the remaining play counter. In yet other implementations, the reset that occurs may simply be a non-change reset, i.e., the remaining play counter may simply be left alone with no increment or decrement thereto. 
     It will be understood that the above discussion relating to the operation of the remaining play counter is intended to also apply to the mathematical complement of remaining play counter, i.e., a plays completed counter that reflects the number of feature game plays that have occurred and are eligible to be compared against a maximum threshold number of plays that the player is provided as part of the feature game. For example, if the player is permitted three plays, the plays completed counter may start at zero and increment upward by one unit instead of downward with each play of the feature game—when the counter reaches the permitted maximum number of plays, the feature game will be concluded. Similarly, if a feature game play results in the analog to the remaining play counter reset condition (a “completed plays counter reset condition,” for example) being met, then the completed plays counter may be decremented by 0 or more units instead of incremented. As noted above, it is the intent of this disclosure that both types of counter be considered within the scope of the above discussion regarding the remaining play counter. 
     If it is determined in block  524  that the remaining play counter has zero units remaining, or if block  526  has been performed responsive to determining in block  520  that the remaining play counter reset condition has been met, the technique may proceed to block  528 , in which a further determination may be made as to whether all displayed symbol positions, i.e., all symbol positions having symbols displayed therein, display feature game symbols. In the event that not all of the symbol positions display feature game symbols, the technique may return to block  504 , and a further input indicative of a play of the feature game may be received. 
     If it is determined in block  528  that all of the displayed symbols are feature game symbols, or if it is determined in block  524  that the remaining play counter has zero units remaining, the feature game may terminate, proceeding to block  530 , in which a determination may be made as to what the winnings are associated with the feature game symbols that are displayed in the array of symbol positions as of the termination of the feature game. The array of symbol positions may then be reset in block  532 , e.g., to an array with first and second dimensions that are set to be equal to the initial values of those dimensions in the main game prior to any growth of the second dimension. The technique may then proceed to block  534 , in which the feature game concludes and the electronic gaming machine returns to presenting the main game for play. Any credits or points that result from play of the feature game may be transferred to the player&#39;s credit or point pool for the main game. 
     As will be apparent from the above discussion, the feature game has the potential to be playable by the player until either of two potential conditions are met—either the player runs out of available plays to use in playing the feature game, or the player manages to completely fill in the array of symbol positions with feature game symbols. It will be understood that the latter condition may be fulfilled for an array of symbol positions even if the array of symbol positions could potentially be grown to a larger size—if the array of symbol positions is, at its current growth state, filled with displayed feature game symbols, then this may be deemed to terminate the feature game. 
     It will be further understood that each feature game symbol that is newly displayed in a symbol position in the array of symbol positions during the feature game as a result of a play of the feature game may remain “stuck” in place, i.e., not replaced with another symbol, for the duration of the feature game. 
     The awards or prizes that are associated with the player in conjunction with the termination of the feature game may be determined according to various rules. For example, the player may be awarded an amount of credits or points for each feature game symbol that is displayed at the conclusion of the feature game. Alternatively, the player may be awarded different tiers of points or credits based on the number of feature game symbols displayed at the conclusion of the feature game. In some implementation, players may be awarded a jackpot award, e.g., significantly larger than non-jackpot awards that may be earned in the feature game, when all of the symbol positions in the array of symbol positions at the conclusion of the feature game display feature game symbols (a “blackout” condition). In some such implementations, the size of the jackpot awarded for achieving a blackout condition may vary based on the amount of growth in the array of symbol positions, e.g., achieving a blackout condition on a 6×5 array of symbol positions may result in an award of points or credits that is higher than the award of points or credits that occurs when a blackout condition is achieved on a 5×4 array of symbol positions. 
       FIGS.  6  through  17    are provided for further insight as to the user experience that a player may encounter when playing a game such as that described above. It will be recognized that the depicted examples are merely representative of some particular outcomes that may be encountered by a player, and that the outcomes that are encountered during play of a main game and/or feature such as are described herein will, of course, differ from game play to game play. 
       FIG.  6    depicts an example GUI for a main game including a persistent array growth mechanism for an array of symbol positions.  FIG.  6    depicts a graphical user interface (GUI)  600  that may be displayed by an electronic gaming machine. The GUI  600  of  FIG.  6    is configured to present a main game for play by a player. The main game is a symbol-based game in which an array  602  of symbol positions  604  (only two are called out, but 15 symbol positions are present) is provided. The array  602  may have a first dimension along direction  606  and a second dimension along direction  608 ; the second dimension may be variable, i.e., able to be changed during game play in response to an array growth condition being met (the dimensions  606  and  608  are provided for reference; they would generally not be depicted as part of the GUI  602 ). It will be recognized that in some implementations, the first dimension may instead be along direction  608  and the second dimension along direction  606 . In this example, the array  602  may have a second dimension that may be able to be grown to a maximum value of six, although other maximum values may be used instead depending on various factors, e.g., display size, desired game performance/return-to-player, etc. 
     To facilitate discussion, various portions of  FIGS.  6  through  17    are shown in broken lines; these are provided for the readers reference and do not necessarily form part of the GUI  600 . For example, each row (or potential row should the array  602  be grown to its maximum size) in the array  602  is provided with a numeric callout to the left of the array  602 , and each column in the array  602  is provided with an alphabetic callout above the array  602 . In a further example, broken lines are used to indicate symbol positions  604  that may be part of the array  602  when the array  602  has been grown to its maximum state. In some implementations, the GUI  602  may actually show similar graphics to indicate to the player the extent of further growth that may occur in the array  602 , although in other implementations, such graphical indicators may be omitted. 
     It will be understood that reference herein to an array of symbol positions is intended to refer to the array of symbol positions that will be used to show symbols  610  that are visible to the player and that are actively used to determine game results for a current play of the game. For example, in some implementations, an electronic gaming machine may, for each game play, actually select symbols  610  for all potential symbol positions that may exist when the array is in its maximum growth state—even if the array is currently in a less-than-maximum growth state (as shown in  FIG.  6   ). For example, in the context of  FIG.  6   , symbols  610  may be selected for both symbol positions  604  in rows 1 through 3, but also rows 4 through 6—however, only the symbols  610  that are associated with symbol positions  604  in rows 1 through 3 would actually be displayed and the array  602  of symbol positions  604  would thus be considered to only constitute the symbol positions  604  in rows 1 through 3 (the symbols  610  that are associated with symbol positions in rows 4 through 6 would either not be displayed at all or would be displayed but obscured by some other graphic, e.g., a padlock to indicate that they may be “unlocked” if the array  602  is grown). In some implementations, symbols  610  may actually be selected and displayed in all actual and potential symbol positions  604  of the array  602 , but the array  602  may be considered to only consist of the symbol positions  604  for which a symbol  610  is both displayed and used to determine an outcome for the current game play. For example, in some implementations, when symbols are shown in symbol positions  604  that are not part of the array  602  (because the array  602  has not been grown sufficiently to include them), those symbols  610  may be shown in a visually different format to emphasize that they are not actively being used in determining game outcomes—the player, however, would still see them (and see how such symbols would have increased their winnings had they been included in determining game outcomes for the current play) and may be incentivized to continue playing in the hopes that they will be able to grow the array  602  so as to actually be able to have the symbols  610  that are shown in symbol positions  604  that are currently outside of the array  602  be included for determining game outcomes in the future. 
     Also shown in  FIG.  6    are various on-screen controls; these may optionally be omitted and provided via physical buttons on an electronic gaming machine. Such controls may include, for example, bet or wager increment/decrement buttons  624 , a spin or play button  618 , a max bet button  626 , and an information button  628 . The bet or wager increment/decrement buttons  624  may be used to provide inputs to the electronic gaming machine that allow the amount that is wagered on each play of the main game to be adjusted upward or downward, as appropriate. The bet max button  626  may be used to set the wager or bet level to the maximum value that the electronic gaming machine is configured to permit. The information button  628  may be used to launch a secondary GUI that may provide instructions on how to play the game, what the potential winning awards are, etc. The play or spin button  618  may be used to initiate a play of the main game, e.g., to initiate a “spin” or selection of symbols  610  for the symbol positions  604  in the array  602 . 
     Information regarding game status may also be provided via informational displays or controls, such as the bet level indicator  620  and the total win indicator  622 . The bet level indicator  620  may indicate the total amount, e.g., in credits or points, that will be wagered on an outcome of the main game responsive to a play of the game, e.g., initiated via selecting the play button  618 . The total win indicator  622  may indicate the amount of credits that are available to the player in the game; the indicated amount may be increased responsive to the player adding credits, e.g., from an external source, or responsive to credits that are awarded due to play of the main game and/or feature game (which is discussed later). 
     As can be seen in  FIG.  6   , a random assortment of symbols  610  has been displayed in the symbol positions  604  of the array  602 ; such symbols may be evaluated to determine if any winning symbol combinations have been displayed along any of the paylines that the electronic gaming machine is configured to evaluate. 
       FIG.  7    depicts the example GUI of  FIG.  6    in an example game state for the main game in which an array growth symbol is displayed in one of the symbol positions. In  FIG.  7   , it can be seen that the symbols  610  of  FIG.  6    have been replaced, e.g., responsive to a play of the main game initiated by an input received via the play button  618 , with new symbols  610 , including an array growth symbol  612  (to be clear, the array growth symbol  612  is also a symbol  610 ). The array growth symbol  612 , in this case, is an arrow pointing upwards, but any desired symbol or types of symbols may be used for the array growth symbol. In this example, the array growth condition is satisfied when one or more array growth symbols  612  are displayed in the array  602  of symbol positions  604 . Thus, the electronic gaming machine may, in connection with the display of the array growth symbol  612 , cause the second dimension of the array  602  to increase by one unit. 
       FIG.  8    depicts the example GUI of  FIG.  6    after the second dimension of the array  602  of symbol positions  604  has been increased by one unit. As can be seen, the symbols  610  selected for display that are shown in  FIG.  7    are retained in  FIG.  8   , the array  602  has been grown in size to include the symbol positions  604  on row 4 (newly added symbol positions  616 , which are emphasized, in this example, by a glowing halo effect around row 4), and additional symbols  610  have been caused to be displayed in the symbol positions  604  that were newly added to the array  602  as result of the array growth. In some implementations, if the symbols  610  that are displayed in the symbol positions  604  that were newly added include one or more array growth symbols  612  that cause the array growth condition to be satisfied again, then a further growth of the array  602  may be caused to occur. However, in other implementations, such further growth may not be allowed to occur, e.g., a maximum of only one array growth operation may occur per game play. 
     While not shown, additional array growth symbols  612  that may be displayed in future feature game plays and that satisfy the array growth condition may cause additional growth of the array  602  of symbol positions  604  (up to the maximum second dimension of the array  602  permitted). 
       FIG.  9    depicts the example GUI of  FIG.  8    after feature game trigger symbols meeting a feature game trigger condition have been displayed. As can be seen, feature game trigger symbols  614  have been shown in the array  602  of symbol positions  604 ; the feature game trigger symbols  614  are also symbols  610  (although not called out as such). In this case, there are six feature game trigger symbols  614 , collectively, shown in the symbol positions  604  of the array  602 , which, in this example, satisfies a feature game trigger condition that requires at least six feature game trigger symbols  614  to be displayed in the array  602  of symbol positions  604 . 
     It will be noticed that the feature game trigger symbols that are displayed are shown as continuous blocks within columns B and D. In some implementations, the subsets of symbols  610  from which symbols  610  may be selected for display in each of columns A-E may be associated with information that identifies the sequence or order of such symbols  610  within the subset, e.g., analogous to a virtual reel strip, and there may, in some implementations, be sequentially adjacent symbols within each subset that are feature game trigger symbols  614 , which may make it more likely for such continuous blocks of feature game trigger symbols to be displayed. In some such implementations, there may be one or more blocks of sequentially adjacent feature game trigger symbols  614  that each have a number of feature game trigger symbols  614  that equals the permissible maximum second dimension value for the array  602 . Such an arrangement would, in the example above, permit the feature game trigger condition discussed above for this example to potentially be met based on the selection of symbols from a single subset of symbols, e.g., from a single virtual reel strip. For example, if each column A-E displays symbols selected from a different corresponding subset of symbols  610 , and each subset of symbols included  100  symbols in which six sequentially adjacent symbols were feature game trigger symbols  614 , then there would be a 1 in 100 chance for each of the columns when the array  602  is in its fully grown state (in this example, having six rows) to show the entire contiguous block of feature game trigger symbols  614 , as shown in  FIG.  10    (in  FIG.  10   , the array has been expanded to have a second dimension with a value of 6). This may be visually appealing to the player in addition to significantly increasing their chances of satisfying the feature game trigger condition. In other implementations, however, there may be feature game trigger symbols that are arranged differently within each subset of symbols, e.g., not necessarily all in a sequentially adjacent manner. 
       FIG.  11    depicts an example GUI for a feature game that is initialized based on the main game state shown in the example GUI of  FIG.  9   , i.e., with a second dimension with a value of 4. The feature game, in this example, retains much of the graphical appearance of the main game, retaining the array  602  of symbol positions  604  in the growth state that the array  602  was in when the feature game was triggered. Additionally, the symbols  610  that are shown in each of the symbol positions  604  in the array  602  are the same as they were in the main game when the feature game was triggered. In some implementations, however, the symbols displayed in the array of symbol positions at the start of the feature game may be randomly selected as opposed to re-using the symbols shown in the array of symbol positions upon triggering of the feature game. 
     As discussed earlier, the feature game symbols may be different from the feature game trigger symbols or may be the same, depending on the implementation. In some implementations, they may effectively be the same except in appearance, e.g., a different graphic may be used for the feature game symbol in place of the graphic for the feature game trigger symbol, but the number and sequential positioning of each such symbol within each subset of symbols may remain the same. In such implementations, the only real difference between identical feature game trigger symbols and the feature game symbols may be in how the symbols are used in the main game and the feature game. For example, in the main game, the display of such symbols may, as discussed above, be used to determine if a feature game trigger condition has been met, whereas in the feature game, the display of such symbols may determine an award that is determined at the conclusion of the feature game and may also cause the remaining plays counter to be reset; such symbols may also be treated as “sticky” in the feature game as opposed to non-sticky in the main game. 
     In some implementations, the feature game symbols may, like the feature game trigger symbols, be included in one or more sets of symbols from which symbols are selected during game play. In some implementations, the set or sets of symbols from which symbols are selected for display during main game play may not have any feature game symbols but may instead have at least one feature game trigger symbol, and the set or sets of symbols from which symbols are selected for feature game play may not have any feature game trigger symbols but may instead have at least one feature game symbol. 
     In the depicted example, the feature game symbols are depicted by money bag symbols and the feature game trigger symbols by dollar signs. When the feature game is initiated, the dollar sign symbols (feature game trigger symbols) may, for example, be replaced by money bag symbols (feature game symbols). In view of the above discussion, however, it will be appreciated that should the same symbol(s) be used for both the feature game trigger symbols and the feature game symbols, there may be no apparent difference between the symbols 
     It will be noted that the area below the array  602  has, however, been updated to reflect the different considerations for game play that may be relevant for the feature game. For example, the wager amount indicator  620  has been replaced with a “spins left” counter  630  (a “remaining play counter” in the previous discussion above) that indicates the number of feature game plays remaining—in this case, the counter reflects that the player has three spins or plays of the feature game remaining. The total amount won indicator  622  has also been replaced with a feature game win indicator  632 , which may indicate to the player how much they have accrued in winnings from the feature game play thus far, e.g., if the feature game were to conclude without any further winnings the displayed amount would, in some implementations, be the amount or minimum amount that the player would win as a result of playing the feature game. In some other implementations, this information may be displayed in conjunction with the total amount won indicator  622  or not at all. The bet increment/decrement button  624 , the max bet button  626 , and the information button  628  have all been hidden/removed from view, although this is optional. 
       FIG.  12    depicts the example GUI of  FIG.  11    after a play of the feature game. As can be seen, the plays remaining indicator  630  has been decremented by one unit responsive to play of the feature game, and the symbol positions  604  in the array  602  that did not have any feature game symbols  615  displayed have had newly selected symbols  610  displayed therein. In this particular implementation, the feature game is configured to not make determinations regarding winning patterns of symbols as was done in the main game. In effect, the only outcome of the feature game play that resulted in the GUI of  FIG.  11    is that the plays remaining indicator  630  was decremented by one unit and new symbols  610  were selected and displayed for some of the symbol positions  604 ; no change to the player&#39;s credits and no additional growth of the array  602  occurred. 
       FIG.  13    depicts the example GUI of  FIG.  11    after another play of the feature game in which an array growth symbol  612  is displayed in one of the symbol positions  604 . While this results in the second dimension of the array  602  being incremented by 1 unit, as occurred earlier with respect to  FIGS.  7  and  8   , the plays remaining counter  630  may nonetheless be decremented by one more unit since no feature game symbol  615  was displayed as a result of the most recent play of the feature game. As discussed earlier, in some implementations, symbols selected responsive to a game play (be it of the main game or the feature game) may be selected from different sets of symbols. In some such instances, one of the sets of symbols may have feature game symbols but no array growth symbols, and another of the sets of symbols may have array growth symbols but no feature game symbols, which may allow for scenarios in which a game play, e.g., of the feature game, may potentially result in either one or more array growth symbols being displayed or one or more feature game symbols being displayed, but never a combination of both symbols. It will be recognized, however, that other implementations may be configured to select symbols from a set of symbols that includes both feature game symbols and array growth symbols, thereby allowing for potential instances in which both types of symbol are selected for display responsive to the same input provided via the play button  618 . 
       FIG.  14    depicts the example GUI of  FIG.  11    after the second dimension of the array  602  of symbol positions  604  has been increased by one unit. This increase of the second dimension is similar to that shown in  FIG.  8    but adds a fifth row of newly added symbol positions  616  to the array  602 , along with symbols that are selected for display therein. 
       FIG.  15    depicts the example GUI of  FIG.  14    after a further play of the feature game in which a feature game symbol has been newly displayed in the GUI. As can be seen, one of the newly displayed symbols is another feature game symbol  615  that is shown in symbol position D 4  (shaded darker than the other feature game symbols  615 ), the display of which, for this particular implementation, satisfies the remaining plays counter reset condition. The remaining plays counter reset condition, in this example, causes the remaining plays counter  630  to be reset to its initial value when one or more feature game symbols  615  are newly displayed as the result of a feature game play. In this example, the remaining play counter  630  has been reset to the initial value of 3. A graphical highlight may emphasize this change to the player, as indicated by the glowing halo effect around the number 3 in the remaining play counter indicator  630 . 
     Feature game play may continue until either the remaining plays counter  630  drops to zero or until the entire array  602  of symbol positions  604  is filled with feature game symbols  615 .  FIG.  16    depicts the example GUI of  FIG.  14    after the feature game play has concluded due to the available play counter being decremented to zero. As can be seen, the feature game play has concluded with no additional growth to the array  602  and with only two additional feature game symbols being shown. 
       FIG.  17    depicts the example GUI of  FIG.  14    after the feature game play has concluded due to all of the symbol positions  604  being filled with feature game symbols  615 . As can be seen, there are still two plays left according to the remaining play counter  630 , but since there are feature game symbols occupying all of the symbol positions in the array  602 , the feature game may be deemed to have been concluded, and the player&#39;s feature game score or winnings may be determined and associated with the player. 
     The condition shown in  FIG.  17    may be referred to as a “blackout” condition, e.g., where all of the available symbol positions may be filled with feature game symbols. Feature games that terminate as a result of such a condition or that display such a condition when the remaining plays reach zero may, in some implementations, be configured to provide for an increased point or credit award. For example, such an outcome may make the player eligible to receive a jackpot award, e.g., a mini, minor, major, or grand jackpot award. In some such implementations, the size of the jackpot award may be based on the amount by which the array  602  has been grown by at the time the blackout condition occurs. For example, in the depicted array  602 , if a blackout condition is obtained with no growth (3×5 array), the player may be credited or awarded with a mini jackpot. If a blackout condition is obtained with one extra row (4×5 array), then the jackpot may be a minor jackpot; if obtained with two extra rows (5×5 array), then the jackpot may be a major jackpot. And if obtained with three extra rows (6×5 array), then the jackpot may be a grand jackpot. 
     Feature games such as that described above may belong to a class of feature games that are commonly referred to as “hold &amp; spin” games, referring to the game mechanic in which certain symbols, once displayed, are “held” in place for future plays (spins) of the game. Thus, each game play of such games may be thought of as including a “hold” phase in which any feature game symbols are caused to be “held” in place followed by a game play (spin) in which the non-feature game symbols are replaced based on, for example, a new “spin” or selection of symbols. The “spin” refers to the way in which symbols were traditionally selected on non-electronic gaming machines, e.g., by spinning a set of reels. 
     The above-discussed main/feature games with persistent symbol position array growth may provide several advantages in terms of maintaining player interest and thereby potentially increasing the potential revenue that may be generated from an electronic gaming machine providing such games. For example, through appropriate configuration of the symbols within each set, as well as the inclusion of various other features that may allow for tuning of the RTP contribution between various features, main/feature games with persistent symbol position array growth may be configured to provide consistent RTP to the player regardless of what wager or bet level is used to place wagers in the main game. In such implementations, the electronic gaming machine may be configured to allow the player to change their bet level without resetting the array to its original dimensions. This allows the player to switch between higher-denomination wagers and lower denomination wagers, or vice-versa, when the array  602  has been “grown” to a larger size without having to worry about the main game re-setting the symbol array size. This allows the player to throttle up or throttle down their wagering rate without penalty in terms of their RTP, providing greater flexibility to the player and more control over their gaming experience. 
     Such implementations may, for example, be achieved by having multiple sets of symbols, wherein the symbols selected for display in an array of symbol positions having a second dimension of a particular size may be selected from a set of symbols that is associated with that particular size. For example, for a game in which the array can be grown by three levels, and thus have four levels of size (original+three increased sizes), there may be at least four sets of symbols, with at least one different corresponding set of symbols associated with each of the four size levels for the array. In practice, this is similar to having four separate games, each with its own underlying math and symbol sets that are selected such that the RTP for any one of the different array sizes is essentially the same as the for the other array sizes. 
     Since the main variable is the size of the array and since the array size changes dimensionally, there is generally a practical limit to the number of times the array can be grown given the real estate on the display. This, in turn, limits the number of separate symbol sets and RTPs that may need to be adjusted in order to maintain a nearly constant RTP for such a game. In contrast, if array growth symbols were instead to only grow a single column or row by one symbol position, rather than add an entire column or row of symbol positions, the number of different symbol sets that would need to be managed in order to maintain a relatively constant RTP regardless of the growth level would be much greater. 
     For example, if one considers a 3×5 array that is growable to a 6×5 array by adding a new row thereto for each such growth, e.g., as discussed above, at least four sets of symbols might be needed, one for each tier of growth, in order to attain generally equivalent RTPs for each array size. However, if the same 3×5 array were to be growable by one symbol position at a time, e.g., if each column of the array is grown by one symbol position responsive to an array growth symbol being shown in that column (to a max height of 6 symbol positions in any given column), at least 244 sets of symbols would likely need to be separately defined in order to have the same RTP regardless of number of symbol positions being used. This requires significantly more effort and makes the configuration of such implementations dauntingly complex compared to the array-growth games discussed above. 
     In some implementations, there may be an additional feature of such games that provides a separate source of RTP. For example, the total RTP may include contributions from various aspects of the game, such as a portion that is attributable to credits won from outcomes in the main game, another portion that is attributable to credits won from outcomes in the feature game, and one or more other portions that are attributable to other features of the game, such as, for example, a free spins feature. The variations in RTP that may occur in the feature game RTP due to the permanence of the array growth feature from the main game may be caused to be offset by complementary variations in RTP for the other game features, e.g., a free spins feature, that may be modified to have an RTP that increases or decreases in step with the decreases or increases in RTP that the feature game may experience. 
     Main/feature games with persistent symbol position array growth are significantly different from typical main/feature games in that changes that occur to game play in the main game, e.g., the array growth, may persist and carry through to the feature game, thus also changing the underlying mechanics of the feature game. In a typical main game/feature game, modifications to the underlying mechanic of the main game are not carried through to any feature game, thereby allowing the feature game and the main game to effectively operate as separate games. 
     It will be appreciated that while much of the discussion above has focused on examples in the context of an electronic gaming machine, other gaming devices, e.g., smartphones, tablet computing devices, laptop or desktop computers, etc., may also be configured to provide similar implementations and are considered within the scope of this disclosure. It will also be appreciated that while the above examples have focused on the use/award of credits, similar implementations may use/award points, or some other quantifiable item, instead. Credits are to be understood to refer to cashable credits, e.g., credits that are redeemable for a national currency by the player, social gaming credits, e.g., credits that are not redeemable for a national currency by the player, or other similar types of credits. 
     While the disclosure has been described with respect to the figures, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the disclosure. Any variation and derivation from the above description and figures are included in the scope of the present disclosure as defined by the claims.