Patent Publication Number: US-9846995-B2

Title: Wagering game with multiple unlockable arrays

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application 61/676,053, filed on Jul. 26, 2012, which is hereby incorporated by reference in its entirety. 
    
    
     COPYRIGHT 
     A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever. 
     FIELD OF THE INVENTION 
     The present invention relates generally to gaming apparatus and methods and, more particularly, to displaying multiple enhanced arrays that are unlockable. 
     BACKGROUND OF THE INVENTION 
     Gaming terminals, such as slot machines, video poker machines and the like, have been a cornerstone of the gaming industry for several years. Generally, the popularity of such machines with players is dependent on the likelihood (or perceived likelihood) of winning money at the machine and the intrinsic entertainment value of the machine relative to other available gaming options. Where the available gaming options include a number of competing machines and the expectation of winning at each machine is roughly the same (or believed to be the same), players are likely to be attracted to the most entertaining and exciting machines. Shrewd operators consequently strive to employ the most entertaining and exciting machines, features, and enhancements available because such machines attract frequent play and hence increase profitability to the operator. Therefore, there is a continuing need for gaming machine manufacturers to continuously develop new games and improved gaming enhancements that will attract frequent play through enhanced entertainment value to the player. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the present invention, a gaming system for conducting a wagering game includes at least one input device, at least one display device, at least one processor, and at least one memory device. The memory device stores instructions that, when executed by the at least one processor, cause the gaming system to receive a wager in response to an input via the at least one input device, display on the at least one display device a main array with a plurality of symbol-bearing reels, display on the at least one display device a plurality of enhanced arrays, and spin and evaluate the plurality of symbol bearing reels on the main array in response to the wager. The plurality of symbol-bearing reels on the main array includes a plurality of enhanced-array triggers. Each of the plurality of enhanced arrays includes a plurality of symbol-bearing reels and an enhancement feature. The enhancement feature of each enhanced array is different from any other enhancement feature of the plurality of enhanced arrays. Each of the plurality of enhanced arrays is associated with at least one of the plurality of enhanced-array triggers. The instructions further cause the gaming system to spin and evaluate the plurality of symbol-bearing reels on the enhanced array associated with a displayed enhanced-array trigger in response to the main array displaying at least one enhanced-array trigger. 
     According to another aspect of the invention, a method of conducting a wagering game on a gaming system includes receiving a wager in response to an input via at least one input device, displaying a main array including a plurality of symbol-bearing reels on at least one display device, displaying a first enhanced array and a second enhanced array on at least one display device, and spinning and evaluating the plurality of symbol-bearing reels on the main array in response to receiving a wager. The plurality of symbol-bearing reels on the main array includes a first enhanced-array trigger symbol associated with only the first enhanced array and a second enhanced-array trigger symbol associated with only the second enhanced array. Each of the enhanced arrays includes a plurality of symbol-bearing reels and an enhancement feature. The enhancement feature of each enhanced array is different from the enhancement features of any other enhanced array. The plurality of symbol-bearing reels on the first enhanced array are spun and evaluated in response to the first enhanced-array trigger symbol being displayed on the at least one display. The plurality of symbol-bearing reels on the second enhanced array are spun and evaluated in response to the second enhanced-array trigger symbol being displayed on the at least one display. 
     According to yet another aspect of the invention, a method of conducting a wagering game on a gaming system includes receiving a wager in response to an input via at least one input device, displaying a main array having a plurality of symbol-bearing reels on at least one display device, and displaying a plurality of enhanced arrays on at least one display device. The plurality of symbol-bearing reels on the main array includes a plurality of enhanced-array triggers. Each of the plurality of enhanced arrays includes a plurality of symbol-bearing reels and an enhancement feature. The enhancement feature of each enhanced array is different from any other enhancement feature of the plurality of enhanced arrays. Each of the plurality of enhanced arrays is associated with at least one of the plurality of enhanced-array triggers. The plurality of symbol-bearing reels on the main array are spun and evaluated in response to the received wager. The plurality of symbol-bearing reels of each enhanced array are spun and evaluated in response to the associated enhanced array-trigger being displayed on the main array. 
     Additional aspects of the invention will be apparent to those of ordinary skill in the art in view of the detailed description of various embodiments, which is made with reference to the drawings, a brief description of which is provided below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a free-standing gaming terminal according to an embodiment of the present invention. 
         FIG. 2  is a schematic view of a gaming system according to an embodiment of the present invention. 
         FIG. 3  is an image of an exemplary basic-game screen of a wagering game displayed on a gaming terminal, according to an embodiment of the present invention. 
         FIG. 4A  is an exemplary screen having a main array and three locked enhanced arrays. 
         FIG. 4B  is the exemplary screen of  FIG. 4A  having one of the enhanced arrays unlocked. 
         FIG. 4C  is the exemplary screen of  FIG. 4A  having all of the enhanced arrays unlocked. 
         FIG. 5  is a flowchart for an algorithm that corresponds to instructions executed by a controller in accord with at least some aspects of the disclosed concepts. 
     
    
    
     While the invention is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. 
     DETAILED DESCRIPTION 
     While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated. For purposes of the present detailed description, the singular includes the plural and vice versa (unless specifically disclaimed); the words “and” and “or” shall be both conjunctive and disjunctive; the word “all” means “any and all”; the word “any” means “any and all”; and the word “including” means “including without limitation.” 
     Referring to  FIG. 1 , there is shown a gaming terminal  10  similar to those used in gaming establishments, such as casinos. With regard to the present invention, the gaming terminal  10  may be any type of gaming terminal and may have varying structures and methods of operation. For example, in some aspects, the gaming terminal  10  is an electromechanical gaming terminal configured to play mechanical slots, whereas in other aspects, the gaming terminal is an electronic gaming terminal configured to play a video casino game, such as slots, keno, poker, blackjack, roulette, craps, etc. The gaming terminal  10  may take any suitable form, such as floor-standing models as shown, handheld mobile units, bartop models, workstation-type console models, etc. Further, the gaming terminal  10  may be primarily dedicated for use in conducting wagering games, or may include non-dedicated devices, such as mobile phones, personal digital assistants, personal computers, etc. Exemplary types of gaming terminals are disclosed in U.S. Pat. No. 6,517,433 and Patent Application Publication Nos. US2010/0069160 and US2010/0234099, which are incorporated herein by reference in their entireties. 
     The gaming terminal  10  illustrated in  FIG. 1  comprises a cabinet  11  that may house various input devices, output devices, and input/output devices. By way of example, the gaming terminal  10  includes a primary display area  12 , a secondary display area  14 , and one or more audio speakers  16 . The primary display area  12  or the secondary display area  14  may be a mechanical-reel display, a video display, or a combination thereof in which a transmissive video display is disposed in front of the mechanical-reel display to portray a video image superimposed upon the mechanical-reel display. The display areas may variously display information associated with wagering games, non-wagering games, community games, progressives, advertisements, services, premium entertainment, text messaging, emails, alerts, announcements, broadcast information, subscription information, etc. appropriate to the particular mode(s) of operation of the gaming terminal  10 . The gaming terminal  10  includes a touch screen(s)  18  mounted over the primary or secondary areas, buttons  20  on a button panel, bill validator  22 , information reader/writer(s)  24 , and player-accessible port(s)  26  (e.g., audio output jack for headphones, video headset jack, USB port, wireless transmitter/receiver, etc.). It should be understood that numerous other peripheral devices and other elements exist and are readily utilizable in any number of combinations to create various forms of a gaming terminal in accord with the present concepts. 
     Input devices, such as the touch screen  18 , buttons  20 , a mouse, a joystick, a gesture-sensing device, a voice-recognition device, and a virtual input device, accept player input(s) and transform the player input(s) to electronic data signals indicative of the player input(s), which correspond to an enabled feature for such input(s) at a time of activation (e.g., pressing a “Max Bet” button or soft key to indicate a player&#39;s desire to place a maximum wager to play the wagering game). The input(s), once transformed into electronic data signals, are output to a CPU for processing. The electronic data signals are selected from a group consisting essentially of an electrical current, an electrical voltage, an electrical charge, an optical signal, an optical element, a magnetic signal, and a magnetic element. 
     Turning now to  FIG. 2 , there is shown a block diagram of the gaming-terminal architecture. The gaming terminal  10  includes a central processing unit (CPU)  30  connected to a main memory  32 . The CPU  30  may include any suitable processor(s), such as those made by Intel and AMD. By way of example, the CPU  30  includes a plurality of microprocessors including a master processor, a slave processor, and a secondary or parallel processor. CPU  30 , as used herein, comprises any combination of hardware, software, or firmware disposed in or outside of the gaming terminal  10  that is configured to communicate with or control the transfer of data between the gaming terminal  10  and a bus, another computer, processor, device, service, or network. The CPU  30  comprises one or more controllers or processors and such one or more controllers or processors need not be disposed proximal to one another and may be located in different devices or in different locations. The CPU  30  is operable to execute all of the various gaming methods and other processes disclosed herein. The main memory  32  includes a wagering game unit  34 . In one embodiment, the wagering game unit  34  may present wagering games, such as video poker, video black jack, video slots, video lottery, etc., in whole or part. 
     The CPU  30  is also connected to an input/output (I/O) bus  36 , which can include any suitable bus technologies, such as an AGTL+frontside bus and a PCI backside bus. The I/O bus  36  is connected to various input devices  38 , output devices  40 , and input/output devices  42  such as those discussed above in connection with  FIG. 1 . The I/O bus  36  is also connected to storage unit  44  and external system interface  46 , which is connected to external system(s)  48  (e.g., wagering game networks). 
     The external system  48  includes, in various aspects, a gaming network, other gaming terminals, a gaming server, a remote controller, communications hardware, or a variety of other interfaced systems or components, in any combination. In yet other aspects, the external system  48  may comprise a player&#39;s portable electronic device (e.g., cellular phone, electronic wallet, etc.) and the external system interface  46  is configured to facilitate wireless communication and data transfer between the portable electronic device and the CPU  30 , such as by a near-field communication path operating via magnetic-field induction or a frequency-hopping spread spectrum RF signals (e.g., Bluetooth, etc.). 
     The gaming terminal  10  optionally communicates with the external system  48  such that the terminal operates as a thin, thick, or intermediate client. In general, a wagering game includes an RNG for generating a random number, game logic for determining the outcome based on the randomly generated number, and game assets (e.g., art, sound, etc.) for presenting the determined outcome to a player in an audio-visual manner. The RNG, game logic, and game assets are contained within the gaming terminal  10  (“thick client” gaming terminal), the external system  48  (“thin client” gaming terminal), or are distributed therebetween in any suitable manner (“intermediate client” gaming terminal). 
     The gaming terminal  10  may include additional peripheral devices or more than one of each component shown in  FIG. 2 . Any component of the gaming terminal architecture may include hardware, firmware, or tangible machine-readable storage media including instructions for performing the operations described herein. Machine-readable storage media includes any mechanism that stores information and provides the information in a form readable by a machine (e.g., gaming terminal, computer, etc.). For example, machine-readable storage media includes read only memory (ROM), random access memory (RAM), magnetic disk storage media, optical storage media, flash memory, etc. 
     Referring now to  FIG. 3 , there is illustrated an image of a basic-game screen  50  adapted to be displayed on the primary display area  12  or the secondary display area  14 . The basic-game screen  50  portrays a plurality of simulated symbol-bearing reels  52 . Alternatively or additionally, the basic-game screen  50  portrays a plurality of mechanical reels or other video or mechanical presentation consistent with the game format and theme. The basic-game screen  50  also advantageously displays one or more game-session credit meters  54  and various touch screen buttons  56  adapted to be actuated by a player. A player can operate or interact with the wagering game using these touch screen buttons or other input devices such as the buttons  20  shown in  FIG. 1 . The CPU operate(s) to execute a wagering game program causing the primary display area  12  or the secondary display area  14  to display the wagering game. 
     In response to receiving a wager, the reels  52  are rotated and stopped to place symbols on the reels in visual association with paylines such as paylines  58 . The wagering game evaluates the displayed array of symbols on the stopped reels and provides immediate awards and bonus features in accordance with a pay table. The pay table may, for example, include “line pays” or “scatter pays.” Line pays occur when a predetermined type and number of symbols appear along an activated payline, typically in a particular order such as left to right, right to left, top to bottom, bottom to top, etc. Scatter pays occur when a predetermined type and number of symbols appear anywhere in the displayed array without regard to position or paylines. Similarly, the wagering game may trigger bonus features based on one or more bonus triggering symbols appearing along an activated payline (i.e., “line trigger”) or anywhere in the displayed array (i.e., “scatter trigger”). The wagering game may also provide mystery awards and features independent of the symbols appearing in the displayed array. 
     In accord with various methods of conducting a wagering game on a gaming system in accord with the present concepts, the wagering game includes a game sequence in which a player makes a wager and a wagering game outcome is provided or displayed in response to the wager being received or detected. The wagering game outcome is then revealed to the player in due course following initiation of the wagering game. The method comprises the acts of conducting the wagering game using a gaming apparatus, such as the gaming terminal  10  depicted in  FIG. 1 , following receipt of an input from the player to initiate the wagering game. The gaming terminal  10  then communicates the wagering game outcome to the player via one or more output devices (e.g., primary display  12  or secondary display  14 ) through the display of information such as, but not limited to, text, graphics, static images, moving images, etc., or any combination thereof. In accord with the method of conducting the wagering game, the CPU transforms a physical player input, such as a player&#39;s pressing of a “Spin Reels” touch key, into an electronic data signal indicative of an instruction relating to the wagering game (e.g., an electronic data signal bearing data on a wager amount). 
     In the aforementioned method, for each data signal, the CPU (e.g., CPU  30 ) is configured to process the electronic data signal, to interpret the data signal (e.g., data signals corresponding to a wager input), and to cause further actions associated with the interpretation of the signal in accord with computer instructions relating to such further actions executed by the controller. As one example, the CPU causes the recording of a digital representation of the wager in one or more storage media (e.g., storage unit  44 ), the CPU, in accord with associated computer instructions, causing the changing of a state of the storage media from a first state to a second state. This change in state is, for example, effected by changing a magnetization pattern on a magnetically coated surface of a magnetic storage media or changing a magnetic state of a ferromagnetic surface of a magneto-optical disc storage media, a change in state of transistors or capacitors in a volatile or a non-volatile semiconductor memory (e.g., DRAM), etc. The noted second state of the data storage media comprises storage in the storage media of data representing the electronic data signal from the CPU (e.g., the wager in the present example). As another example, the CPU further, in accord with the execution of the instructions relating to the wagering game, causes the primary display  12 , other display device, or other output device (e.g., speakers, lights, communication device, etc.) to change from a first state to at least a second state, wherein the second state of the primary display comprises a visual representation of the physical player input (e.g., an acknowledgement to a player), information relating to the physical player input (e.g., an indication of the wager amount), a game sequence, an outcome of the game sequence, or any combination thereof, wherein the game sequence in accord with the present concepts comprises acts described herein. The aforementioned executing of computer instructions relating to the wagering game is further conducted in accord with a random outcome (e.g., determined by a RNG) that is used by the CPU to determine the outcome of the game sequence, using a game logic for determining the outcome based on the randomly generated number. In at least some aspects, the CPU is configured to determine an outcome of the game sequence at least partially in response to the random parameter. 
     Referring now to  FIGS. 4A-4C , a wagering game screen  100  is shown. The wagering game screen  100  includes a main array  102  and three enhanced arrays  104   a - 104   c . The main array  102  includes a plurality of main-array reels  106   a - 106   e . A first enhanced array  104   a  includes a plurality of first-enhanced-array reels  108   a - 108   e . Similarly, a second enhanced array  104   b  includes a plurality of second-enhanced-array reels  110   a - 110   e  and a third enhanced array  104   c  includes a plurality of third-enhanced-array reels  112   a - 112   e . The main array  102  may be presented in either a base game or a bonus event of the wagering game. Similarly, the enhanced arrays  104   a - 104   c  may be displayed with the main array  102  or as a separate bonus feature. The enhanced arrays  104   a - 104   c  are locked until a triggering condition is met. 
     Referring now to  FIG. 4A , each of the enhanced arrays  104   a - 104   c  is visually associated with a respective enhanced-array trigger symbol  114   a - 114   c  when locked. Additionally, this display informs the player of the particular enhanced-array trigger symbol  114   a - 114   c  required to unlock the particular enhanced array  104   a - 104   c . When locked, the enhanced arrays  104   a - 104   c  are not eligible to provide an award to a player in response to a winning combination. It is contemplated that other methods may be used to signify when an enhanced array is not currently in play. 
     Each enhanced array  104   a - 104   c  also includes at least one enhancement feature  116   a - 116   c  associated with it. As will be described in detail in connection with  FIG. 4B , the first enhanced array  104   a  is associated with a “wild reels” enhancement feature  116   a . As will be described in connection with  FIG. 4C , the second enhanced array  104   b  is associated with a “random wilds” enhancement feature  116   b  and the third enhanced array  104   c  is associated with a “reduced symbol set” enhancement feature  116   c . It is contemplated that other enhancement features may be used such as free spins, an increased number of bonus event trigger symbols, respins, additional paylines, clumped symbols, locking symbols, loaded reels, etc. Additionally, multiple enhancements may be used on any of the three enhanced arrays  104   a - 104   c  and/or the enhanced arrays  104   a - 104   c  may share some enhancement features. 
     Referring now to  FIG. 4B , the main array  102  is shown displaying a triggering condition to unlock an enhanced array. In this embodiment, the triggering condition is any enhanced-array trigger symbol  114   a - 114   d  being displayed on the rightmost main-array reel  106   e . The enhanced-array trigger symbol  114   a - 114   d  “unlocks” the particular enhanced array  104   a - 104   c  or particular enhanced arrays associated with it. After the wagering game outcome is determined and a first-enhanced-array trigger symbol  114   a  is displayed, the first enhanced array  104   a  (i.e., the enhanced array associated with trigger symbol  114   a ) is unlocked and the display of the first enhanced array  104   a  is altered. The illustrated “wild reels” enhancement feature  116   a  ( FIG. 4A ) is utilized in the first enhanced array  104   a  by the gaming system. The gaming system selects a random number of the first-enhanced-array reels  108   a - 108   e  to be replaced with wild reels. In the illustrated embodiment, the number of reels to be replaced ranges from two to four. The gaming system then selects the positions of the first-enhanced-array reels  108   a - 108   e  to be replaced with the wild reels. In the illustrated embodiment, the CPU  30  has randomly selected the three rightmost first-enhanced-array reels  108   c - 108   e  to be replaced by wild reels. In some embodiments, the selected wild reels are locked in place while the remaining two leftmost first-enhanced-array reels  108   a  and  108   b  are spun. A game outcome is determined based on the arrangement of symbols randomly selected from spinning the two leftmost first-enhanced-array reels  108   a  and  108   b  combined with the wild symbols already selected on the three rightmost first-enhanced-array reels  108   c - 108   d.    
     Referring now to  FIG. 4C , a multiple-enhanced-array trigger symbol  114   d  is displayed on the fifth reel  106   e  of the main array  102  and is associated with all three enhanced arrays  104   a - 104   c . It is contemplated that additional combinations of enhanced-array trigger symbols  114   a - 114   d  may be included that are associated with more than one, but less than all, of the enhanced arrays  104   a - 104   b . As described above, the “wild reels” enhancement feature  116   a  ( FIG. 4A ) is applied to the first enhanced array  104   a . In this illustration, the second first-enhanced-array reel  108   b  and the rightmost first-enhanced-array reel  108   e  were selected to be wild reels using the method stated above. 
     The “random wilds” enhancement feature  116   b  ( FIG. 4A ) is applied to the second enhanced array  104   b  when the second enhanced array  104   b  is unlocked. The illustrated “random wilds” enhancement feature  116   b  ( FIG. 4A ) is applied to the second enhanced array  104   b  by the gaming system. The gaming system selects a random number of symbols to be replaced on the second enhanced array  104   b . In the illustrated embodiment, the number of symbols to be replaced ranges from two to five. The gaming system selects the positions of the symbols to be replaced on second-enhanced-array reels  110   a - 110   e  to be replaced by wild symbols. In the illustrated embodiment, the CPU  30  has randomly selected three array positions to be replaced with wild symbols. These array positions are located at the top of the second second-enhanced-array reel  110   b , as well as the top and bottom of the rightmost second-enhanced-array reel  110   e . In some embodiments, the selected wild symbols are locked in place on the second enhanced array  104   b  while the second-enhanced-array reels  110   a - 110   e  are spun. A game outcome is then determined based on the locked wild symbols and on the randomly selected symbols displayed on the remaining positions of the second enhanced array  104   b.    
     The illustrated “reduced symbol set” enhancement feature  116   c  ( FIG. 4A ) is applied to the third enhanced array  104   c  by the gaming system after the third enhanced array  104   c  is unlocked. In the illustrated embodiment, the “reduced symbol set” enhancement feature  116   c  includes a plurality of symbols arranged on the plurality of the third-enhanced-array reels  112   a - 112   e  of the third enhanced array  104   c . The set of symbols on the third-enhanced-array reels  112   a - 112   e  includes symbols used on the main array  102 , but excludes the lowest paying symbols in that set. The number of symbols excluded from the third-enhanced-array reels  112   a - 112   e  may be varied to achieve a desired result. By way of non-limiting example, the set of excluded symbols can be a predetermined set or can be randomly determined by the gaming system during play of the wagering game. 
       FIG. 5  illustrates a schematic depiction of one algorithm that corresponds to at least some instructions that can be executed by the CPU  30  and/or external systems  48  to perform the above described functions associated with the disclosed concepts. By way of non-limiting example, the exemplary algorithm  200  includes receiving a wager, at step  202 , from a player to initiate a wagering game. The wager is placed or otherwise confirmed, for example, using a bill validator  22 , coin acceptor, information reader  24 , or other input device. A main array and enhanced arrays are displayed at step  204  (e.g., the main array  102  and enhanced arrays  104   a - 104   c  of  FIG. 4A ). It is contemplated that the main array and the enhanced arrays can also be displayed prior to initiation of the wagering game. 
     After receiving the wager from the player, a game outcome is generated. In the illustrated embodiment, the main array includes a plurality of symbol-bearing reels that are spun and evaluated at step  206  (e.g., the main-array reels  106   a - 106   e  of  FIGS. 4A-4C ). It is determined, at decision box  208 , whether a triggering condition has occurred that enables play of any enhanced arrays (e.g., as shown in  FIG. 4B , the first-enhanced-array trigger symbol  114   a  being displayed on the rightmost main-array reel  106   e  allows play of the first enhanced array  104   a ). If a triggering condition has not occurred, an award determination is made at step  212  to evaluate whether the main array resulted in an award to the player. Alternatively, if a triggering condition has occurred, at least one enhanced array associated with the triggering condition is unlocked and the symbol-bearing reels on the unlocked enhanced array are spun and evaluated at step  210 . 
     In the illustrated embodiment, the unlocked enhanced array includes a plurality of symbol-bearing reels (e.g., the first-enhanced-array reels  108   a - 108   e  shown in  FIG. 4B ). It is contemplated that multiple triggering conditions may occur simultaneously and that either all or fewer than all enhanced arrays associated with the triggering conditions may be played. It is further contemplated that multiple enhanced arrays may be associated with a single trigger symbol (e.g., the multiple-enhanced-array trigger symbol  114   d  shown in  FIG. 4C ). After the enhanced array has been spun and evaluated at step  210 , an award determination is made at step  212  to evaluate whether the main array, enhanced array, both, or neither resulted in an award to the player. These awards are based on, for example, combinations of symbols displayed on the main array and symbols displayed on any unlocked array. The player is provided with any determined awards at step  214  and play of the wagering game may continue. 
     In some embodiments, play of the unlocked enhanced arrays can unlock other of the enhanced arrays or cause the main array to respin. For example, play of the first enhanced array  104   a  can result in displaying a second-enhanced-array trigger symbol  114   b  that unlocks the second enhanced array  104   b . Or, in another example, play of the first enhanced array  104   a  can result in a respin symbol that causes the main array  102  to respin one or more times. Furthermore, the respinning of the main array  102  can potentially unlock other enhanced arrays, for example, a third-enhanced-array trigger symbol  114   c  unlocks the third enhanced array  104   c.    
     In some embodiments, the number of enhanced-array trigger symbols  114   a - 114   d  increases if a free-spin bonus game is triggered on the main array  102 . In this embodiment, the plurality of main-array reels  106   a - 106   e  includes only three enhanced-array trigger symbols  114   a - 114   c  during the base game, each of the enhanced-array trigger symbols  114   a - 114   c  being able to unlock a single and distinct one of the enhanced arrays  104   a - 104   c . When a free-spin bonus is initiated, as indicated by an information area  118  ( FIG. 4C ), the multiple-enhanced-array trigger symbol  114   d  is added to the plurality of symbol positions on at least one of the main-array reels  106   a - 106   e . The multiple-enhanced-array trigger symbol  114   d  is able to unlock all three enhanced arrays  104   a - 104   c  simultaneously. Alternatively, during a free-spin bonus game, all of the single, enhanced-array trigger symbols  114   a - 114   c  convert to multiple-enhanced-array trigger symbols  114   d.    
     In yet other embodiments, the number of enhanced-array trigger symbols  114   a - 114   d  does not change when the free-spin bonus is initiated. In this embodiment, an enhanced array that becomes unlocked due to a triggering condition remains unlocked and is spun and evaluated for the remainder of the free spins. For example, if the free-spin bonus has ten free spins and the first enhanced array  104   a  is unlocked during the third free spin, the first enhanced array  104   a  remains unlocked and is spun and evaluated for each of the remaining seven spins (in addition to the third spin). 
     While the present devices have been described using a single-symbol trigger on the rightmost main-array reel  106   e , it is contemplated that a single-symbol trigger may be implemented on any of the main-array reels  106   a - 106   e . In alternative embodiments, a combination of symbols or a specific placement of symbols may be required to unlock the enhanced arrays. This requirement can include a trigger with three symbols where all three symbols indicate the enhanced array to be unlocked. For example, in reference to  FIG. 4B , two additional first-enhanced-array trigger symbols  114   a  would be required to be displayed on any of the main-array reels  106   a - 106   e . Alternatively, the three first-enhanced-array trigger symbols  114   a  could be required to be located in a specific location or orientation (e.g., all three symbols must be located in a top position on any of the main-array reels  106   a - 106   e  of the main array  102 ). In yet another alternative, the three symbols could be different from one another (e.g., one symbol identifies the enhanced array to be unlocked and the other two symbols are generic bonus symbols). 
     Each of these embodiments and obvious variations thereof is contemplated as falling within the spirit and scope of the claimed invention, which is set forth in the following claims.