Patent Publication Number: US-2023162575-A1

Title: Electronic gaming systems and methods with short term persistence

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of and claims the benefit of U.S. Pat. Application No. 17/205,667, filed 18 March, 2021, which claims the benefit of priority to U.S. Provisional Pat. Application No. 63/020,730, filed 06 May, 2020, entitled “ELECTRONIC GAMING SYSTEMS AND METHODS WITH SHORT TERM PERSISTENCE,” the contents and disclosures of which are hereby incorporated by reference in their entireties. 
    
    
     TECHNICAL FIELD 
     The field of disclosure relates generally to casino gaming, and more particularly to systems and methods for providing short term persistence within electronic games. 
     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. 
     BRIEF DESCRIPTION 
     In one aspect, a method for providing a persistent feature in an electronic game is provided. The method includes providing the electronic game that simulates spinning of a plurality of reels. The electronic game defines a play area that includes portions of each reel of the plurality of reels after each spin. The method also includes generating a first spin result that includes a first feature symbol on a first reel of the plurality of spinning reels and a second feature symbol on a second reel adjacent to the first reel. The method further includes triggering a value feature based on the occurrence of at least one feature symbol appearing on the first reel and at least one feature symbol appearing on the second reel in first spin result. The value feature causes the electronic game to award value feature symbols that appear on another reel of the plurality of reels other than the first reel and the second reel. The method also includes, upon initiation of a second spin, displaying an animation of moving one or more of the first feature symbol and the second feature symbol one or more positions of the reel upon which the feature symbol occurs. The method further includes overlaying the one or more moved feature symbols during the second spin of the plurality of reels. The method also includes triggering the value feature for the second spin when at least one feature symbol appears on both the first reel and on the second reel. 
     In another aspect, a non-transitory computer-readable medium storing instructions is provided. When executed by an electronic gaming device, the instructions cause the electronic gaming device to provide an electronic game that simulates spinning of a plurality of reels. The electronic game defines a play area that includes portions of each reel of the plurality of reels after each spin. The instructions also cause the electronic gaming device to generate a first spin result that includes a first feature symbol on a first reel of the plurality of spinning reels and a second feature symbol on a second reel adjacent to the first reel. The instructions also cause the electronic gaming device to trigger a value feature based on the occurrence of at least one feature symbol appearing on the first reel and at least one feature symbol appearing on the second reel in first spin result. The value feature causes the electronic game to award value feature symbols that appear on another reel of the plurality of reels other than the first reel and the second reel. The instructions also cause the electronic gaming device to, upon initiation of a second spin, display an animation of moving one or more of the first feature symbol and the second feature symbol one or more positions of the reel upon which the feature symbol occurs. The instructions also cause the electronic gaming device to overlay the one or more moved feature symbols during the second spin of the plurality of reels. The instructions also cause the electronic gaming device to trigger the value feature for the second spin when at least one feature symbol appears on both the first reel and on the second reel. 
     In yet another aspect, an electronic gaming device providing an electronic game is provided. The electronic gaming device includes a display device, a memory including a plurality of reel strips that include common symbols and feature symbols, and a processor configured to execute instructions. When executed, the instructions cause the processor to provide an electronic game that simulates spinning of a plurality of reels. The electronic game defines a play area that includes portions of each reel of the plurality of reels after each spin. The instructions also cause the processor to generate a first spin result that includes a first feature symbol on a first reel of the plurality of spinning reels and a second feature symbol on a second reel adjacent to the first reel. The instructions also cause the processor to trigger a value feature based on the occurrence of at least one feature symbol appearing on the first reel and at least one feature symbol appearing on the second reel in first spin result. The value feature causes the electronic game to award value feature symbols that appear on another reel of the plurality of reels other than the first reel and the second reel. The instructions also cause the processor to upon initiation of a second spin, display an animation of moving one or more of the first feature symbol and the second feature symbol one or more positions of the reel upon which the feature symbol occurs. The instructions also cause the processor to overlay the one or more moved feature symbols during the second spin of the plurality of reels. The instructions also cause the processor to trigger the value feature for the second spin when at least one feature symbol appears on both the first reel and on the second reel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       An example embodiment of the subject matter disclosed will now be described with reference to the accompanying 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. 
         FIGS.  4 A and  4 B  illustrate an example user interface within which an electronic game with a short-term persistence feature is provided by an electronic device, such as the gaming devices shown in  FIGS.  1  and  2 A , the mobile gaming devices shown in  FIG.  2 B , and the end user devices shown in  FIG.  2 C . 
         FIGS.  5 A and  5 B  illustrate an example embodiment in which a bonus game with these persistent features is activated. 
         FIGS.  6 A,  6 B, and  6 C  illustrate the example user interface within which another electronic game with an expanding wilds feature is provided by an electronic device, such as the gaming devices shown in  FIGS.  1  and  2 A , respectively, the mobile gaming devices shown in  FIG.  2 B , and the end user devices shown in  FIG.  2 C . 
         FIGS.  7 A and  7 B  illustrate an expanding wilds feature (a “minor expanding wilds” feature) when a feature symbol appears in one of the secondary positions of the feature columns. 
         FIG.  8    is a flowchart of an example method for providing short term persistence features in an electronic game. 
     
    
    
     DETAILED DESCRIPTION 
     Conventional slot-style games provide a randomness in a spin outcome and in award evaluation for that spin. For example, a game may utilize a random number generator to produce a spin outcome for the reels and that spin outcome is evaluated in conjunction with a pay table to determine an award amount to provide to the player. A particular round of a game, or game instance, typically concludes after a single spin and award evaluation, with no persistent features carrying over from one round to the next. Such conclusivity of each spin includes a simple display and resolution. However, providing games with features having short term persistence requires additional processing steps between game instances that may involve both feature tracking between instances and display features to provide a clear indication to players how the persistent features are carrying over from instance to instance. 
     A gaming system and methods are described that provide games with short term persistent features. The gaming system provides feature symbols which may trigger a persistent feature that carries across game instances. In an example embodiment, the gaming system provides a five reel game that includes “wild” feature symbols scattered throughout reels one and two and “value” feature symbols scattered throughout reels three, four, and five (e.g., a “cash on reels” symbol showing a numeric value of a potential award). The value feature symbols display award amounts in conjunction with the feature symbol are initially inactive but can be activated during a given game instance. When a spin result includes one or more feature symbols on both reels one and two, the value feature symbols on reels in a feature play area (e.g., reels three, four, and five) are activated. During award evaluation, the wild feature symbols may combine with the value feature symbols in the feature play area to generate wins (e.g., in payline evaluation, ways evaluation, or the like). Any value feature symbols that appear in one or more wins provide the value award amounts for those wins (e.g., in lieu of, or in addition to, a base symbol win evaluation). In some embodiments, the gaming system may provide reel expansion of the feature play area when the value feature is activated, possibly growing the reel height of reels three, four, and five by one or more additional rows in height, thereby exposing a larger feature play area and thus potentially more value feature symbols to include in the award evaluation. 
     Further, in the example embodiment, the gaming system provides persistence and associated display indicators based on the feature symbols appearance on reels one and two. When any feature symbol appears on reels one or two during a game instance, award evaluation is performed as described above. During a next spin, the gaming system retains the feature symbols on reels one and two from the prior spin, shifting those feature symbols up (or down) one row on their associated reel. If a feature symbol shifts above (or below) the first row (or last row), that persistent feature symbol is removed. These persisted feature symbols overlay the reel symbol that might normally appear during the next spin result. Since the feature symbols on reels one and two are used to activate the value feature symbols in the feature play area, the short term persistence of those feature symbols on reels one and two can improve award outcomes during subsequent spins. 
     The gaming system also provides a visual display animation for the persistent feature. When a feature symbol persists between two instances, the gaming system illustrates the persistent feature by showing an animation of the persistent feature symbol(s) shifting up (or down) on reels one and two during the next spin. For example, when a new spin is initiated, the gaming system may initiate spinning of the reels and show the persistent feature symbols overlaying their respective reels and symbol positions as the persistent feature symbol(s) are moved up (or down) one row. Once movement of the persistent feature symbols is complete, the gaming system concludes the spin and displays the spin result with the persistent feature symbols overlaying their respective symbol positions. In some embodiments, the gaming system may provide additional animation to the feature symbols when the value feature symbols are activated, thereby allowing the player to visually witness the conditions of the value feature activation. Accordingly, such display animation makes clear to the player how the persistent feature is operating from one spin to the next and how the feature symbols affect the underlying award evaluation being performed by the gaming system. 
       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 XLTM 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’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 ArcTM 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 HelixTM 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 black jack, 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’s credit value, a ticket reader  224  which reads bar-coded tickets or other media or mechanisms for storing or indicating a player’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’s level of patronage (e.g., to the player’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’s player loyalty card, a patron’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’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’s “cash in” selections, wagering game results and a player’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’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. 
       FIGS.  4 A and  4 B  illustrate an example user interface  402  within which an electronic game with a short-term persistence feature is provided by an electronic device, such as the gaming devices  104 ,  200  shown in  FIGS.  1  and  2 A , respectively, the mobile gaming devices  256  shown in  FIG.  2 B , and the end user devices  264  shown in  FIG.  2 C . In the example embodiment, the electronic game is provided on a social gaming platform (e.g., a non-gambling site or application based on virtual currencies) and may be accessed by players through end user devices  264 . In other embodiments, the electronic game is provided on gaming devices  104 ,  200  at gambling venues (e.g., regulated gaming casinos or other wager gaming sites). 
     In the example embodiment, the electronic game is a reel-based game that uses five reels to present a play area  404  having three rows  410 A,  410 B,  410 C (collectively, “rows  410 ”) and five columns (or “reels”)  412 A,  412 B,  412 C,  412 D,  412 E (collectively, “columns  412 ” or “reels  412 ”). The columns/reels may be referred to herein based on their ordinal number from left to right (e.g., the first reel  412 A, the second reel  412 B, the third reel  412 C, and so forth), and rows may be referred to herein based on their ordinal number from top to bottom (e.g., the first row  410 A, the second row  410 B, the third row  410 C, and so forth). 
     The example game provides a feature symbol at various locations on the reels  412 . In the following examples, the feature symbol includes an image of a bear holding a symbol frame. On the first and second reels  412 A,  412 B, the feature symbols are “wild” symbols and have the term “WILD” displayed within the symbol frame. On the third, fourth, and fifth reels  412 C,  412 D,  412 E, the feature symbols include a numeric credit award value displayed within the symbol frame, and these feature symbols may also act as “value” symbols (e.g., “cash on reels” symbols, or “what you see is what you get (WYSIWIG) symbols”). These third, fourth, and fifth reels  412 C- 412 E are also referred to herein as a feature play area  414 . During base game play, the value feature symbols appearing in the feature play area  414  are inactive unless a value feature has been activated as described herein. In other words, when the value feature is inactive, the value feature symbols are treated as common symbols (e.g., for purposes of payline evaluations, Reel Power® evaluations, or the like), and when they are activated, the value feature symbols provide an award based on award value included with the symbol frame (e.g., in real or virtual credits). Further, in some embodiments, the value feature symbols may appear in a first state when the value feature is inactive (e.g., subdued or muted colors relative to other symbols, greyed out, statically displayed, or the like, during or after a spin in which the value feature was not triggered). The value feature symbols may be converted to appear in a second state when the value feature has been activated (e.g., brighter colors equivalent or greater than other symbols, animated symbols, or the like, during or after a spin in which the value feature is triggered). 
     A first spin result  400  is depicted in  FIG.  4 A . In the example embodiment, the value feature is activated based on the appearance of the feature symbols in the first and second columns  412 A,  412 B in the spin result  400 . More specifically, when at least one feature symbol appears in the first column  412 A and at least one feature symbol appears in the second column  412 B, the value feature is activated. In the example embodiment, any value feature symbols appearing in a winning combination (e.g., in a winning payline under payline evaluation, in an “of-a-kind” win under ways evaluation, or the like) provide an award based on the award value appearing in the symbol frame of the feature symbol(s) contributing to the winning combination(s) (e.g., in lieu of, or in addition to, a base symbol win evaluation). In another embodiment, activation of the value feature causes the electronic game to award all of the values shown on any of the value symbols appearing within the feature play area  414 . 
     In the example shown here, feature symbols (e.g., “WILDS”) appear at the third row  410 C of the first column  412 A and the second row  410 B of the second column  412 B after a base game spin (e.g., based on RNG output by the game processing backend system  314  shown in  FIG.  3   ). Since this spin result includes at least one feature symbol in both the first and second columns  412 A,  412 B, the value feature is activated. Also in the example shown here, the feature play area  414  includes a value symbol in row  410 C of the third column  412 C (e.g., a bear graphic with “2M”, or 2 million credits). Since the value feature is activated, the game is configured to evaluate the spin outcome for any winning combinations that include value feature symbols. In this example, the game performs a left-to-right ways evaluation that identifies a three-of-a-kind combination including the two wild feature symbols of reel one  412 A and reel two  412 B, as well as a value symbol in reel  412 C. As such, in addition to any other common symbol evaluations, the game additionally awards 2 million credits for the value symbol that appears in this winning combination (e.g., adding to the award total for the spin). In another embodiment, the game may be configured to award any and all values of value feature symbols appearing in the feature play area  414 . In some embodiments, the game is configured to provide an outcome evaluation of the spin result and associated award based on payline evaluation, Reel Power® evaluation, ways evaluation, or the like. 
     In some embodiments, the game spins and resolves the first two reels  412 A,  412 B while the remaining reels  412 C,  412 D, and  412 E continue to spin. In situations where the results on the first two reels  412 A,  412 B trigger the value feature, the game may provide an expansion of the feature play area  414  (e.g., randomly based on RNG result, based on a trigger defined in a pay table, or the like). When expansion is triggered, the game grows the feature play area  414  (e.g., reels  412 C,  412 D, and  412 E) by one or more rows above (or below) the feature play area  414  as shown. Such expansion thereby exposes additional symbol positions on each of the reel  412 C,  412 D, and  412 E, thereby providing a greater chance of exposing more value feature symbols and a greater chance of achieving winning combinations involving those feature symbols. The game may expand the reels  412 C,  412 D, and  412 E by one, two, three, four, or five rows. In some embodiments, the number of expansion rows is determined based on an RNG result and a weighted table. In some embodiments, the number of expansion rows is determined based on the pay table. The game may provide a visualization to the reel expansion to highlight that the reels are expanding during a particular spin. For example, the reels  412 C,  412 D, and  412 E may grow by one or more rows as the reels  412 C,  412 D, and  412 E are spinning and resolve the spin after expansion is complete. In some embodiments, the reels  412 C,  412 D, and  412 E contract in size after award is complete. In other embodiments, the reel expansion may persist for as long as the value feature persists. In some embodiments, the reel expansion may contract by one row per spin until the original size of the feature play area  414  is reached. In the example shown in  FIG.  4 A , no reel expansion is achieved. 
     The example electronic game additionally provides an enhancement to the value feature described above. In the example embodiment, after evaluation of the value feature for a given spin, the value feature includes short-term persistence for the next spin(s). More specifically, after the value feature has been activated (e.g., as in the first spin result  400 ), on the next spin, any feature symbols that had previously appeared on the first and second reels  412 A,  412 B are moved up one position and are retained and overlaid onto the next spin outcome, falling off the top (or bottom) when they reach the edge of their associated reel  412 . 
       FIG.  4 B  illustrates a next spin result  420  following the first spin result  400  shown in  FIG.  4 A . In this example, the two wild feature symbols from the first spin result  400  have each moved up one position (e.g., up one row  410 ) in their respective columns  412 A,  412 B. More specifically, the “wild” feature symbol of the first column  412 A has moved up from the third row  410 C to the second row  410 B, and the “wild” feature symbol of the second column  412 B has moved up from the second row  410 B to the first row  410 A. The game positions these feature symbols at their new positions for the current spin. The game then performs the current spin, respinning all of the reels  412  to generate a new spin outcome. As the spin occurs, the two feature symbols are overlaid onto the reels  412 A,  412 B and an animation is provided showing the two wild feature symbols shifting up and overlaying the spinning reels  412 A,  412 B beneath. Upon conclusion of the spinning of reels  412 A and  412 B, the current spin result shown in  FIG.  4 B  illustrates the persistent wild feature symbols replacing whatever symbols that would have normally appeared in those positions. Since the conditions for the value feature is satisfied by this next spin result  420 , the value feature is again activated. Here, the game awards a three-of-a-kind two way, awarding the award values shown in both value feature symbols appearing in reel  412 C since they both appear in winning combinations. In other embodiments, the game awards the player for any or all value feature symbols appearing in the feature play area  414 . Further, in the example shown here, the expansion feature is also activated, causing the feature play area  414  to expand vertically by one row at the top of the feature play area  414 . 
     After the spin result  420  shown in  FIG.  4 B , one of the feature symbols is at the top row  410 A (e.g., the feature symbol in column  412 B). As such, during the next spin, the game again moves all of the feature symbols appearing in the first and second columns  412 A,  412 B up one position. Any feature symbols that were already in the first row  410 A are removed and, as such, may conclude the persistence of the value feature (e.g., unless another feature symbol appears naturally in the second column  412 B). In other words, as the feature symbols move up from spin to spin, the feature symbols “fall off” the top of the reel and are removed from play. This symbol movement provides short term persistence of the game feature over potentially several consecutive spins, potentially causing additional subsequent spins to trigger value feature and possibly the expansion feature as well. 
     In some embodiments, when one of the feature symbols has reached the first row  410 A but the feature symbol(s) in the other column have not yet reached the first row  410 A, the feature symbol in the first row  410 A may linger without falling off until the feature symbol in the other column catches up. For example, presuming the spin result  420  shown in  FIG.  4 B , since the feature symbol in column  412 B is in the first row  410 A but the feature symbol in column  412 A has not yet made it to the first row, the game may retain the feature symbol in the first row  412 A of column  412 B and may move up the feature symbol to row  410 A of column  412 A for the next spin. This lingering enhancement allows the game feature to persist a little longer in certain scenarios. 
     In some situations, additional feature symbols may naturally appear in the first and second columns  412 A,  412 B while the persistence enhancement is active. For example, if the spin result of the underlying reel  412 A,  412 B causes another feature symbol to appear in another position on either of those reels  412 A,  412 B, that feature symbol will additionally be treated under the movement and feature activation methods described here. In other words, there may be multiple feature symbols persisting and moving on either or both of the reels  412 A,  412 B, and as long as at least one feature symbol appears on both the first reel  412 A and the second reel  412 B after movement of the previous feature symbols, then the value feature will continue to be activated during the next spin. 
     In some embodiments, the game may provide a reel growth enhancement when the value feature is active. For example, whenever the value feature is activated, the game may provide a chance at also growing the third, fourth, and fifth reels  412 C,  412 D,  412 E (and thus the size of the feature play area  414  which, in a base configuration, is 3x3). In the spin result  400  shown in  FIG.  4 A , the reel growth enhancement was not activated, and thus the feature play area remained as having only three rows  410 . In the spin result  420  shown in  FIG.  4 B , the reel growth enhancement was activated, causing an additional row  410 X to be added to the feature play area  414  (e.g., exposing additional symbols from each of the reels  412 C,  412 D,  412 E in a 4x3 feature play area  414 ). In some embodiments, reel expansion can be one additional row  410 X, two additional rows (not shown), or more. In the example embodiment, the game provides a maximum reel growth to a size of five rows (e.g., two rows of expansions), to a maximum of 5x3 feature play area  414 . The determination of reel expansion can be done, for example, based on an RNG result of the game processing backend system  314  shown in  FIG.  3    and referencing of a lookup table  322  for reel growth, thereby allowing game designers to control RTP of the features described herein. 
     In some embodiments, the reel expansion enhancement may persist in conjunction with the persistence of the feature symbols and the value feature. For example, the game may provide the feature play area  414  in a base configuration, such as the 3x3 feature play area  414  shown in  FIG.  4 A . When the value feature first activates, the game may allow for the possibility of reel expansions (e.g., causing an additional RNG and table lookup for potential reel growth). While consecutive spins continue to activate the value feature, any reel expansion previously achieved is maintained for the next spin. Once the next spin result does not activate the value feature, the game may collapse the feature play area  414  back to its base size. The expansion of the reels in combination with the activation and persistence of the feature symbols provides greater potential to achieve additional value feature symbols in the feature play area  414  over multiple spins. 
     In some embodiments, the game may provide a partial respin feature with persistence during a single game instance. For example, and still referring to the initial spin result shown in  FIG.  4 B , after the initial spin result is shown and triggers the value feature, but before evaluating the initial spin result for award, the game may provide a free partial respin of reels  412 C,  412 D,  412 E. During this partial respin, the first and second reels  412 A and  412 B are held in place, and any previously achieved value feature symbols achieved in the feature play area  414  during the initial spin result persist and are held in place in the feature play area  414  as the reels  412 C,  412 D,  412 E are respun underneath the persistent value feature symbols. The persistent value feature symbols overlay their associated positions in the respin results but allow for additional value feature symbols to potentially appear in other positions in the feature play area  414 . Such a persistent respin feature may be triggered based on RNG result, based on a weighted table, or based on pay table. In some embodiments, the persistent respin feature may be retriggered consecutively multiple times, persisting any previously-achieved value feature symbols in the feature play area from one respin to the next. In the example embodiment, the game performs an awards evaluation (e.g., ways evaluation, payline evaluation) without the value awards after the initial spin but before the respin. As such, any common symbol evaluation and award is computed for the initial spin and all respins, while the value feature symbols are awarded only once. In other embodiments, full award evaluation including value feature symbols may occur after the initial spin and after each respin, thereby potentially awarding some value feature symbols multiple times. The game may provide an animation showing the payment evaluations prior to respins and may provide an animation illustrating the triggering of the partial respin feature. 
       FIGS.  5 A and  5 B  illustrate an example embodiment in which a bonus game with these persistent features is activated. In the example embodiment, the electronic game provides a bonus game with persistence features whenever three or more bonus game symbols appear in the feature play area  414  (e.g., scatter symbols, shown here as “SCATTER”). In another embodiment, the electronic game provides a bonus game whenever the value feature is activated (e.g., as described above) and additionally when the feature play area  414  shows three or more bonus game symbols.  FIG.  5 A  shows an example spin result  500  in which the value feature is active due to the two feature symbols appearing in columns  412 A,  412 B, and additionally where there are three bonus game symbols appearing in the feature play area  414 . As such, the game activates a bonus game.  FIG.  5 B  illustrates awarding the player 10 free spins for the bonus game. In some embodiments, activation of the value feature may cause reel expansion as mentioned above. Accordingly, such reel expansion additionally grows the feature play area such as to increase the probability of three or more bonus game symbols occurring. In other words, triggered reel expansion can lead to greater chance of triggering the bonus game. 
     During bonus game play, in the example embodiment, the electronic game initially provides the 3x5 play area  404  as shown in  FIG.  4 A  and also provides the potential for the value feature and expansion feature shown and described above. The electronic game may also replace any or all of the original reels  412  with new reel strips (e.g., augmenting the feature symbols on the first and second reels  412 A,  412 B to control how often the value feature activates during bonus game play, augmenting the value feature symbols appearing on the third, fourth, and fifth reels  412 C,  412 D,  412 E or the reel growth lookup table  322  to control game experience or RTP for the bonus game). As such, the bonus game lasts through the free spins, and may provide any or all of the value features, the persistence enhancements, and the reel growth enhancements described herein during bonus game play. 
     In some embodiments, during bonus game play, the fifth reel  412 E always includes at least one value feature symbol, where in other embodiments, the fifth reel  412 E includes only value feature symbols and optionally bonus game symbols. In some embodiments, the occurrence of two or more bonus game symbols during bonus game play triggers an award of additional free spins. 
     In some embodiments, the bonus game provides variability in what persistent features are provided during bonus game play. For example, in one embodiment, at the beginning of bonus game play, the game provides a wheel with a wheel spin to determine which bonus game feature to provide during bonus game play. Each slice of the wheel includes a bonus award that can be applied before or during the free spins of bonus game play. Example features may include a locked wild feature symbol on the first reel  412 A or the second reel  412 B or both (e.g., wild feature symbol(s) that persist in its position during all free spins), fixed reel expansion (e.g., a persistent expansion of the feature play area  414  by one or more rows), automatic reel expansion trigger (e.g., triggering the expansion feature during every spin), additional free games, or any of the progressive jackpots (e.g., minor, major, grand, or the like). 
       FIGS.  6 A,  6 B, and  6 C  illustrate the example user interface  402  within which another electronic game with an expanding wilds feature is provided by an electronic device, such as the gaming devices  104 ,  200  shown in  FIGS.  1  and  2 A , respectively, the mobile gaming devices  256  shown in  FIG.  2 B , and the end user devices  264  shown in  FIG.  2 C . In the example embodiment, the electronic game is provided on a social gaming platform (e.g., a non-gambling site or application based on virtual currencies) and may be accessed by players through end user devices  264 . In other embodiments, the electronic game is provided on gaming devices  104 ,  200  at gambling venues (e.g., regulated gaming casinos or other wager gaming sites). 
     In the example embodiment, the electronic game is a reel-based game that uses five reels to present a play area  604  having three rows  610 A,  610 B,  610 C (collectively, “rows  610 ”) and five columns (or “reels”)  612 A,  612 B,  612 C,  612 D,  612 E (collectively, “columns  612 ” or “reels  612 ”). The columns/reels may be referred to herein based on their ordinal number from left to right (e.g., the first reel  612 A, the second reel  612 B, the third reel  612 C, and so forth), and rows may be referred to herein based on their ordinal number from top to bottom (e.g., the first row  610 A, the second row  610 B, the third row  610 C, and so forth). 
     This example game provides two feature columns  614 A,  614 B associated with an expanding wilds feature of the game (e.g., the second column  612 B and the fourth column  612 D, collectively “feature columns 614”). Each of the two feature columns  614  further includes a primary position  606 A,  606 B (e.g., the positions in the second row  610 B of feature columns  614 A,  614 B), where the other positions within the two feature columns  614 A,  614 B are referred to herein as “secondary positions” (not separately numbered in these figures). The reel strips associated with the two feature columns  614  are preconfigured to include one or more occurrences of a feature symbol (e.g., a lightning bolt in this example embodiment) scattered throughout the reel strip, and the occurrence of that feature symbol within the feature columns triggers various expanding wild features described herein. 
     A first view  600  of an example spin result of the game is depicted in  FIG.  6 A . In the example embodiment, a primary expanding wilds feature is activated based on the appearance of the feature symbol in either of the primary positions  606 . More specifically, when the feature symbol appears in either or both of the primary positions  606 A,  606 B of the feature columns  614 A,  614 B, the primary expanding wilds feature is activated. In the example, the feature symbol appears in the primary position  606 B of the feature column  614 B (e.g., the second row  610 B of the fourth column  612 D). 
       FIG.  6 B  illustrates a transition to a second view  620  after the spin result shown in  FIG.  6 A . In the example embodiment, upon activation of the primary expanding wilds feature, the game replaces the feature column and both adjacent columns with an oversized symbol  616 . The symbol replacement indicates to the player that a game feature has been activated and is being processed. In this example, the Greek god Zeus is shown holding a lightning bolt and is electrifying an orb  618 , which is positioned approximately at the location of the primary position  606 B that activated this feature. 
       FIG.  6 C  illustrates a subsequent transition to a third view  630  of the spin result in which the game applies feature awards to the spin result. In the example embodiment, the game provides two feature awards to the player. The first award is to convert all of the positions under the oversized symbol  616  to wild symbols. Here, all of the symbols appearing in columns  612 C,  612 D, and  612 E are replaced with a wild symbol  626 . Such replacement can improve game results during spin evaluation, for example, payline evaluation, Reel Power® evaluation, or the like. The second award, in the example embodiment, is either a multiplier award  622  (e.g., “10x”, or a ten times multiplier to the spin evaluation) or a jackpot award (e.g., mini, minor, major, or grand jackpots, progressive jackpots, or the like). The game may use a lookup table  322  and RNG result to determine whether the second award is a jackpot award or a multiplier award, and what jackpot or multiplier is awarded. 
     In this example, the game performs a payline evaluation of the spin result and computes a 1,000 credit base award for the payline evaluation. Further, the game also awarded the “10x” multiplier  622 , which the game applies to the base award to generate a 10,000 credit payout  624 . Upon conclusion of this game instance, the game provides the 10,000 credit award to the player and continues with another spin. 
       FIGS.  7 A and  7 B  illustrate an expanding wilds feature (a “minor expanding wilds” feature) when a feature symbol appears in one of the secondary positions  702  of the feature columns  614 . More specifically, in the example embodiment, whenever a feature symbol appears not in the primary position  606  but in a secondary position  702  of one of the feature columns  614 , the game expands the feature symbol to make the entire column  612 D wild. In the example view  700  shown in  FIG.  7 A , the feature symbol appears in the third row  610 C of the fourth column  614 D (e.g., one of the two secondary positions of feature column  614 D), which causes the game to perform a minor symbol expansion. Upon activation of the minor symbol expansion feature, and referring now to a subsequent view  720  of the game shown in  FIG.  7 B , the game overlays an oversized wild symbol  704  across all three positions of column  612 D. For evaluation purposes, each symbol position in column  612 D is considered as having a wild symbol in it. As such, when the game performs payout evaluation for the spin, the presence of the oversized wild symbol  704  may increase the payout results for the player. 
     In some situations, multiple feature symbols may appear simultaneously within the feature columns  614  after a spin. In some embodiments, when a feature symbol appears in both primary positions  606 A and  606 B, the game may overlay the play area  604  with a 3x5 oversized symbol and may similarly convert all of the spaces to wilds and may provide a second reward or multiple second rewards for the major symbol expansion. In some embodiments, when a feature symbol appears in a secondary position of both of the feature columns  614 , each feature column  614  may be replaced with the 1x3 wild symbol. In some embodiments, when a feature symbol appears in one of the primary positions  606  of one of the feature columns  614  and another feature symbol appears in one of the secondary positions of the other feature column  614 , the game may apply the major symbol expansion based on the primary position occurrence as well as the minor symbol expansion based on the secondary position occurrence. 
       FIG.  8    is a flowchart of an example method  800  for providing short term persistence features in an electronic game. In some embodiments, the electronic game may be provided on a mobile device of a player, such as the mobile gaming devices  256  shown in  FIG.  2 B  or the end user devices  264  shown in  FIG.  2 C . In other embodiments, the electronic game may be provided on an electronic gaming device such as the gaming devices  104 ,  200  shown in  FIG.  1    and  FIG.  2 A . In the example embodiment, method  800  includes initiation of a next reel spin (e.g., game instance) of the reels  412  at operation  810 . At test  812 , the electronic game determines whether there are persistent feature symbols (e.g., on the first and second reels  412 A,  412 B) that persist from the prior spin at test  812 . If persistent symbols are present, the electronic game determines a movement destination for the persistent feature symbols at operation  820  (e.g., one position up or down on the respective reel  412 A,  412 B, or off the play area). At operation  822 , the electronic game displays a movement animation of the persistent feature symbol(s) moving from an initial position to a destination position or off the play area. At operation  824 , the electronic game displays the persistent feature symbol(s) overlaying their associated destination position(s) on reels  412 A,  412 B as the reels  412  spin. 
     At operation  830 , in the example embodiment, the electronic game resolves the spinning of the first and second reels  412 A,  412 B while the other reels  412 C,  412 D,  412 E of the feature play area  414 . Based on the spin outcomes of the first and second reels  412 A,  412 B, the electronic game determines whether or not to activate the value feature for the current spin at test  832 . In the example embodiment, the electronic game activates the value feature when at least one feature symbol appears on the first reel  412 A and at least one feature symbol appears on the second reel  412 B. If test  832  is successful, the electronic game activates the value feature at operation  840  (e.g., converting the value symbols on the other reels  412 C,  412 D,  412 E from inactive symbols to active symbols). In some embodiments, the electronic game may test  842  whether to expand reels during the current spin, and may expand the reels at operation  844 . 
     In the example embodiment, the electronic game then resolves the remaining reels  412 C,  412 D,  412 E at operation  850 . In some embodiments, the electronic game may test  852  whether or not to activate a partial respin of the remaining reels  412 C,  412 D,  412 E. If a partial respin is activated, the electronic game may provide an award evaluation of common symbols at operation  860  (e.g., a common award evaluation excluding the value award values). At operation  862 , the electronic game performs a partial respin of the other reels  412 C,  412 D,  412 E with persistent value feature symbols. During the partial respin, all value symbols already appearing on the other reels  412 C,  412 D,  412 E are maintained and overlayed in their existing positions as the other reels  412 C,  412 D,  412 E are respun. At operation  870 , the electronic game performs a final award outcome evaluation, awarding both common awards (e.g., paylines, ways wins) and value awards (e.g., adding any value award values that appear in winning combinations into the final award amount). In some embodiments, the method  800  may include a determination whether to trigger a bonus game after operation  870 . The bonus game may provide a number of free spins along with any or all of the game features described herein. 
     A computer, controller, or server, such as those described herein, includes at least one processor or processing unit and a system memory. The computer, controller, or server typically has at least some form of computer readable non-transitory media. As used herein, the terms “processor” and “computer” and related terms, e.g., “processing device”, “computing device”, and “controller” are not limited to just those integrated circuits referred to in the art as a computer, but broadly refers to a microcontroller, a microcomputer, a programmable logic controller (PLC), an application specific integrated circuit, and other programmable circuits “configured to” carry out programmable instructions, and these terms are used interchangeably herein. In the embodiments described herein, memory may include, but is not limited to, a computer-readable medium or computer storage media, volatile and nonvolatile media, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules, or other data. Such memory includes a random access memory (RAM), computer storage media, communication media, and a computer-readable non-volatile medium, such as flash memory. Alternatively, a floppy disk, a compact disc - read only memory (CD-ROM), a magneto-optical disk (MOD), and/or a digital versatile disc (DVD) may also be used. Also, in the embodiments described herein, additional input channels may be, but are not limited to, computer peripherals associated with an operator interface such as a mouse and a keyboard. Alternatively, other computer peripherals may also be used that may include, for example, but not be limited to, a scanner. Furthermore, in the exemplary embodiment, additional output channels may include, but not be limited to, an operator interface monitor. 
     As indicated above, the process may be embodied in computer software. The computer software could be supplied in a number of ways, for example on a tangible, non-transitory, computer readable storage medium, such as on any nonvolatile memory device (e.g. an EEPROM). Further, different parts of the computer software can be executed by different devices, such as, for example, in a client-server relationship. Persons skilled in the art will appreciate that computer software provides a series of instructions executable by the processor. 
     While the invention 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 invention. Any variation and derivation from the above description and figures are included in the scope of the present invention as defined by the claims.