Abstract:
A gaming system and method for conducting a wagering game during which a designated cascade-triggering outcome can cause some symbols to be removed from the display and can move adjacent symbols to cascade and replace the removed symbols in a cascade outcome. A cascade outcome that includes a winning outcome can pay the player a higher value than the same winning outcome that is not included in a cascade outcome.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a U.S. national phase of International Application No. PCT/US2006/025894, filed Jun. 29, 2006, which claims the benefit of priority of U.S. Provisional Patent Application No. 60/694,946, filed Jun. 29, 2005, both of which are incorporated by reference in their 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 machines, and methods for playing wagering games, and more particularly, to a gaming machine having a cascading reel feature. 
     BACKGROUND OF THE INVENTION 
     Gaming machines, 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. 
     One concept that has been successfully employed to enhance the entertainment value of a game is the concept of a “secondary” or “bonus” game that may be played in conjunction with a “basic” game. The bonus game may comprise any type of game, either similar to or completely different from the basic game, which is entered upon the occurrence of a selected event or outcome in the basic game. Generally, bonus games provide a greater expectation of winning than the basic game and may also be accompanied with more attractive or unusual video displays and/or audio. Bonus games may additionally award players with “progressive jackpot” awards that are funded, at least in part, by a percentage of coin-in from the gaming machine or a plurality of participating gaming machines. Because the bonus game concept offers tremendous advantages in player appeal and excitement relative to other known games, and because such games are attractive to both players and operators, there is a continuing need to develop gaming machines with new types of bonus games to satisfy the demands of players and operators. 
     However, in some of the basic games, the player is not as engaged as he or she could be because once the player wins an award, the basic game is finished, and there are no continuing benefits for having achieved a winning outcome. If the basic game does not have a bonus feature or a progressive feature, the player may feel dissatisfied with only the basic game. Alternatively, if the game includes a bonus game and/or progressive game, but the player does not achieve it, the player may feel dissatisfied even after achieving a win in the basic game. 
     Thus, there is a need to allow a player to play a wagering game in which after achieving a winning combination, there is another continuing benefit. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the present invention, a gaming machine is provided. The gaming machine includes an input device for receiving inputs from a player during the wagering game and the inputs including a wager amount. The gaming machine also includes a display for displaying a plurality of symbols that indicate a randomly selected outcome of the wagering game. The plurality of symbols is located on a plurality of reels and the randomly selected outcome is selected from a plurality of outcomes. The plurality of outcomes includes a cascade-triggering outcome and a plurality of winning outcomes. Each of the plurality of winning outcomes having an associated initial game payout. In response to the randomly selected outcome being the cascade-triggering outcome, both a corresponding symbol is moved and the display displays a cascade outcome. In response to the cascade outcome being one of the plurality of winning outcomes, a cascade payout is awarded that is greater than the initial game payout for that one of the plurality of winning outcomes. 
     According to another aspect of the invention, a method of conducting a wagering game on a gaming machine is provided. The method includes conducting the wagering game at a gaming machine. The gaming machine has a plurality of reels with a plurality of symbols that indicate a randomly selected outcome of the wagering game. The randomly selected outcome is selected from a plurality of outcomes and the plurality of outcomes includes a plurality of winning outcomes. Each of the plurality of winning outcomes has an associated initial game payout. At least some of the plurality of symbols are displayed on a pay line. In response to one of the plurality of symbols indicating a cascade-triggering outcome, a corresponding symbol is moved. After moving the corresponding symbol, a cascade outcome is displayed. In response to the cascade outcome being one of the plurality of winning outcomes, a player is awarded a cascade amount that is an amount greater than the initial game payout for that one of the plurality of winning outcomes. 
     According to yet another aspect of the invention, a computer readable storage medium is encoded with instructions for directing a gaming device to perform the above method. 
     According to yet another embodiment of the present invention, a method of conducting a wagering game on a gaming machine is provided. The method includes receiving a wager input into the gaming machine having a plurality of reels. The gaming machine includes a pay table with winning outcomes and corresponding awards for the winning outcomes. A randomly selected outcome is displayed on a plurality of reels and a player is awarded the corresponding award in response to the randomly selected outcome being one of the winning outcomes. Symbols on at least one of the plurality of reels cascade in response to a cascade-triggering outcome being achieved. In response to one of the winning outcomes being achieved after the symbols have cascaded the player is awarded an amount greater than the corresponding award on the pay table in response. 
     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 gaming machine embodying the present invention. 
         FIG. 2  is a block diagram of a control system suitable for operating the gaming machine. 
         FIG. 3  is a screen of the primary display of the gaming machine of  FIG. 1 . 
         FIG. 4  is a subsequent screen of the primary display of  FIG. 3  illustrating a cascading feature according to one embodiment of the present invention. 
         FIG. 5  is a screen of the primary display after the cascade of  FIG. 4  has occurred according to one embodiment of the present invention. 
         FIG. 6  is a screen of the primary display after another cascade according to one embodiment of the present invention. 
         FIG. 7  is a subsequent screen of the primary display of  FIG. 3  illustrating a cascading feature according to another embodiment of the present invention. 
         FIG. 8  is an initial screen of the primary display of the gaming machine of  FIG. 1  according to another embodiment of the present invention. 
         FIG. 9  is a subsequent screen of the primary display of  FIG. 8  illustrating a cascading feature according to one embodiment of the present invention. 
         FIG. 10  is a subsequent screen of the primary display of  FIG. 8  after the cascading of  FIG. 9  according to one embodiment of the present invention. 
         FIGS. 11   a - nn  are a plurality of diagrams illustrating various pay lines according to one embodiment of the present invention. 
     
    
    
     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. 
     Referring to  FIG. 1 , a gaming machine  10  is used in gaming establishments such as casinos. With regard to the present invention, the gaming machine  10  may be any type of gaming machine and may have varying structures and methods of operation. For example, the gaming machine  10  may be an electromechanical gaming machine configured to play mechanical slots, or it may be an electronic gaming machine configured to play a video casino game, such as blackjack, slots, keno, poker, blackjack, roulette, etc. 
     The gaming machine  10  comprises a housing  12  and includes input devices, including a value input device  18  and a player input device  24 . For output the gaming machine  10  includes a primary display  14  for displaying information about the basic wagering game. The primary display  14  can also display information about a bonus wagering game and a progressive wagering game. The gaming machine  10  may also include a secondary display  16  for displaying game events, game outcomes, and/or signage information. While these typical components found in the gaming machine  10  are described below, it should be understood that numerous other elements may exist and may be used in any number of combinations to create various forms of a gaming machine  10 . 
     The value input device  18  may be provided in many forms, individually or in combination, and is preferably located on the front of the housing  12 . The value input device  18  receives currency and/or credits that are inserted by a player. The value input device  18  may include a coin acceptor  20  for receiving coin currency (see  FIG. 1 ). Alternatively, or in addition, the value input device  18  may include a bill acceptor  22  for receiving paper currency. Furthermore, the value input device  18  may include a ticket reader, or barcode scanner, for reading information stored on a credit ticket, a card, or other tangible portable credit storage device. The credit ticket or card may also authorize access to a central account, which can transfer money to the gaming machine  10 . 
     The player input device  24  comprises a plurality of push buttons  26  on a button panel for operating the gaming machine  10 . In addition, or alternatively, the player input device  24  may comprise a touch screen  28  mounted by adhesive, tape, or the like over the primary display  14  and/or secondary display  16 . The touch screen  28  contains soft touch keys  30  denoted by graphics on the underlying primary display  14  and used to operate the gaming machine  10 . The touch screen  28  provides players with an alternative method of input. A player enables a desired function either by touching the touch screen  28  at an appropriate touch key  30  or by pressing an appropriate push button  26  on the button panel. The touch keys  30  may be used to implement the same functions as push buttons  26 . Alternatively, the push buttons  26  may provide inputs for one aspect of the operating the game, while the touch keys  30  may allow for input needed for another aspect of the game. 
     The various components of the gaming machine  10  may be connected directly to, or contained within, the housing  12 , as seen in  FIG. 1 , or may be located outboard of the housing  12  and connected to the housing  12  via a variety of different wired or wireless connection methods. Thus, the gaming machine  10  comprises these components whether housed in the housing  12  or outboard of the housing  12  and connected remotely. 
     The operation of the basic wagering game is displayed to the player on the primary display  14 . The primary display  14  can also display the bonus game associated with the basic wagering game. The primary display  14  may take the form of a cathode ray tube (CRT), a high resolution LCD, a plasma display, an LED, or any other type of display suitable for use in the gaming machine  10 . As shown, the primary display  14  includes the touch screen  28  overlaying the entire monitor (or a portion thereof) to allow players to make game-related selections. Alternatively, the primary display  14  of the gaming machine  10  may include a number of mechanical reels to display the outcome in visual associated to at least one pay line  32 . In the illustrated embodiment, the gaming machine  10  is an “upright” version in which the primary display  14  is oriented vertically relative to the player. Alternatively, the gaming machine may be a “slant-top” version in which the primary display  14  is slanted at about a thirty-degree angle toward the player of the gaining machine  10 . 
     A player begins play of the basic wagering game by making a wager via the value input device  18  of the gaming machine  10 . A player can select play by using the player input device  24 , via the buttons  26  or the touch screen keys  30 . The basic game consists of a plurality of symbols arranged in an array, and includes at least one pay line  32  that indicates one or more outcomes of the basic game. Such outcomes are randomly selected in response to the wagering input by the player. At least one of the plurality of randomly-selected outcomes may be a start-bonus outcome, which can include any variations of symbols or symbol combinations triggering a bonus game. 
     In some embodiments, the gaming machine  10  may also include a player information reader  52  that allows for identification of a player by reading a card with information indicating his or her true identity. The player information reader  52  is shown in  FIG. 1  as a card reader, but may take on many forms including a ticket reader, bar code scanner, RFID transceiver or computer readable storage medium interface. Currently, identification is generally used by casinos for rewarding certain players with complimentary services or special offers. For example, a player may be enrolled in the gaming establishment&#39;s loyalty club and may be awarded certain complimentary services as that player collects points in his or her player-tracking account. The player inserts his or her card into the player information reader  52 , which allows the casino&#39;s computers to register that player&#39;s wagering at the gaming machine  10 . The gaming machine  10  may use the secondary display  16  or other dedicated player-tracking display for providing the player with information about his or her account or other player-specific information. Also, in some embodiments, the information reader  52  may be used to restore game assets that the player achieved and saved during a previous game session. 
     Turning now to  FIG. 2 , the various components of the gaming machine  10  are controlled by a central processing unit (CPU)  34 , also referred to herein as a controller or processor (such as a microcontroller or microprocessor). To provide gaming functions, the controller  34  executes one or more game programs stored in a computer readable storage medium, in the form of memory  36 . The controller  34  performs the random selection (using a random number generator (RNG)) of an outcome from the plurality of possible outcomes of the wagering game. Alternatively, the random event may be determined at a remote controller. The remote controller may use either an RNG or pooling scheme for its central determination of a game outcome. It should be appreciated that the controller  34  may include one or more microprocessors, including but not limited to a master processor, a slave processor, and a secondary or parallel processor. 
     The controller  34  is also coupled to the system memory  36  and a money/credit detector  38 . The system memory  36  may comprise a volatile memory (e.g., a random-access memory (RAM)) and a non-volatile memory (e.g., an EEPROM). The system memory  36  may include multiple RAM and multiple program memories. The money/credit detector  38  signals the processor that money and/or credits have been input via the value input device  18 . Preferably, these components are located within the housing  12  of the gaming machine  10 . However, as explained above, these components may be located outboard of the housing  12  and connected to the remainder of the components of the gaming machine  10  via a variety of different wired or wireless connection methods. 
     As seen in  FIG. 2 , the controller  34  is also connected to, and controls, the primary display  14 , the player input device  24 , and a payoff mechanism  40 . The payoff mechanism  40  is operable in response to instructions from the controller  34  to award a payoff to the player in response to certain winning outcomes that might occur in the basic game or the bonus game(s). The payoff may be provided in the form of points, bills, tickets, coupons, cards, etc. For example, in  FIG. 1 , the payoff mechanism  40  includes both a ticket printer  42  and a coin outlet  44 . However, any of a variety of payoff mechanisms  40  well known in the art may be implemented, including cards, coins, tickets, smartcards, cash, etc. The payoff amounts distributed by the payoff mechanism  40  are determined by one or more pay tables stored in the system memory  36 . 
     Communications between the controller  34  and both the peripheral components of the gaming machine  10  and external systems  50  occur through input/output (I/O) circuits  46 ,  48 . More specifically, the controller  34  controls and receives inputs from the peripheral components of the gaming machine  10  through the input/output circuits  46 . Further, the controller  34  communicates with the external systems  50  via the I/O circuits  48  and a communication path (e.g., serial, parallel, IR, RC, 10bT, etc.). The external systems  50  may include a gaming network, other gaming machines, a gaming server, communications hardware, or a variety of other interfaced systems or components. Although the I/O circuits  46 ,  48  may be shown as a single block, it should be appreciated that each of the I/O circuits  46 ,  48  may include a number of different types of I/O circuits. 
     Controller  34 , as used herein, comprises any combination of hardware, software, and/or firmware that may be disposed or resident inside and/or outside of the gaming machine  10  that may communicate with and/or control the transfer of data between the gaming machine  10  and a bus, another computer, processor, or device and/or a service and/or a network. The controller  34  may comprise one or more controllers or processors. In  FIG. 2 , the controller  34  in the gaming machine  10  is depicted as comprising a CPU, but the controller  34  may alternatively comprise a CPU in combination with other components, such as the I/O circuits  46 ,  48  and the system memory  36 . 
     Turning now to  FIG. 3 , the primary display  14  according to one embodiment of the present invention is illustrated. In this embodiment, the basic game is a slot machine game, with symbols on five different reels  62   a ,  62   b ,  62   c ,  62   d ,  62   e . The reels  62   a - e  may be either traditional mechanical reels, electromechanical reels, or they may be computer-generated images of reels, with each reel composed of a plurality of symbols. In this embodiment, there are multiple pay lines  64  across the various reels  62   a - e . While multiple pay lines  64  are shown, a gaming machine  10  having a single pay line will also work with the present invention. 
     During the basic game, the player places a wager on any number of pay lines  64 . In the illustrated embodiment, the wager may be between one and five credits per pay line  64 . However, in other embodiments, other wager amounts may be made. Once the player has placed the wager, the reels  62   a - e  begin to spin. The result of the spin may be displayed on an outcome indicator  66 , and winning pay lines  64  may be highlighted on the primary display  14 . In the illustrated example, the pay line having three outhouses, a cow, and a wild symbol is a winning pay line (as highlighted in  FIG. 3 ). The player is awarded an initial basic game payout according to a basic game pay table as shown on the outcome indicator  66 . The pay table for the basic game indicates the possible winning combinations of symbols and the initial payout associated with each winning combination prior to any cascading events. For line pays (i.e. winning combinations that must appear on an active pay line), the payout is multiplied by the number of credits wagered on the winning pay line. For scatter pays (i.e. winning combinations that must appear on the display but need not appear on an active pay line), the payout is multiplied by the total number of credits wagered. 
     In addition to winning the initial basic game payout for the symbol combination in  FIG. 3 , the player is given another opportunity to win on the same wager. After a winning combination is achieved, winning symbols  68  (in the case of  FIG. 3 , the three outhouses and the wild symbol) disappear. Symbols  70  above the disappearing symbols cascade down as shown in  FIGS. 4 and 5 . As shown in  FIG. 5 , a new winning combination is created on the highlighted reel, which includes new winning symbols  82 . 
     For the winning symbol combination shown in  FIG. 5 , the initial basic game payout is 100 credits in the pay table. In other words, had the winning symbol combination been achieved in the basic game ( FIG. 3 ), the player would have awarded 100 credits. However, because the outcome is achieved in the cascading event, the player is awarded twice that amount, or 200 credits. As illustrated, the awarded amount (200 credits) for a winning combination that occurs after the cascade is greater than the initial basic game payout (100 credits). This multiplication is displayed to the player in the outcome indicator  66 , which, in this case, includes a multiplier of two. 
     In some embodiments, the new symbols  82  in the winning combination also disappear and symbols  84  above the disappearing symbols  82  cascade down into position, and the player is now rewarded for any new winning combinations. The awarded amount may also be greater than the initial game payout in the pay table for the basic game, or the award that would have been achieved in the first cascading event. 
     In some embodiments, the initial bonus game payout is multiplied by a multiplier and the multiplier is selected by the player. In these embodiments, after the first cascade, the primary display  14  instructs the player to choose one of a plurality of spaceships  86 . Each spaceship  86  hides a multiplier. The selected multiplier is revealed to the player as shown in  FIG. 6 . In the illustrated embodiment, the player selected a five-times multiplier. As a result, the initial basic game payout corresponding to the winning combination achieved by the second cascade is multiplied by five. The multipliers may be any numbers, but in the illustrated embodiment, the multipliers are between three and ten. 
     In other embodiments, if a new winning combination is achieved from the subsequent cascade, the corresponding basic game payout may be multiplied by a randomly selected multiplier. In some embodiments, the multiplier may stay the same for each cascade (e.g., two). In other embodiments, the multiplier may increase as the number of wins per spin increases. For example, achieving a winning combination on the original spin results in the corresponding initial basic game payout being paid out. A winning combination on a first cascade pays twice the corresponding initial basic game payout listed on the pay table for that winning combination. A winning combination on a second cascade pays three times the corresponding initial game payout listed on the pay table for that winning combination, etc. . . . 
     Alternatively, the multiplier may increase by a factor of two (or other number) for each cascade. For example, a winning combination in the first cascade pays twice the corresponding initial basic game payout for that combination. A winning combination in a second cascade pays four times the corresponding initial basic game payout for that combination. A winning combination in a third cascade pays eight times the corresponding initial basic game payout for that combination, and a winning combination in a fourth cascade pays sixteen times the corresponding initial basic game payout for that combination. 
     In some embodiments, the winning symbols  68 ,  82  that disappear are tracked by the gaming machine  10  (or system controller). Once a player reaches a predetermined goal (e.g., five of each symbol, ten of a particular symbol), the player is awarded an extra award. In other words, this is a “symbol-collection” feature. Once the predetermined number of symbols has been collected by the gaming machine  10  (or system controller), the cascading of symbols begins. 
     In some embodiments, the cascading may continue until there are no more winning combinations. In other embodiments, the cascade may stop after a predetermined number of cascades (e.g., one or two). 
     In another embodiment of the present invention, any “hold” symbols involved in a winning combination do not cascade. The “hold” symbol, which may be beneficial to the player, may be “wild” symbols or “scatter” symbols. Turning now to  FIG. 7 , after the winning combination of  FIG. 3  is achieved, the primary display  14  illustrates the winning symbols  68  disappearing and the symbols  70  cascading down. However, unlike the embodiment illustrated in  FIG. 4 , in the embodiment of  FIG. 7 , the “wild” symbol does not disappear. Instead, the “wild” symbol stays and is capable of being used in subsequent winning combinations. Because this increases the player&#39;s odds of winning (or at least the player&#39;s perception of his or her odds of winning), keeping the “wild” symbol in play provides more player satisfaction. 
     Turning now to  FIG. 8 , another embodiment of the present invention will be described. In this embodiment, the primary display  14  includes fourteen “micro” reels  100   a - n . Each reel displays a single symbol in a particular location, unlike traditional reels, which often display three or more symbols per column. 
     When the player places a wager, the player decides how many credits to wager per line. In the displayed embodiment, there are forty lines and the player may place a wager of up to 5 credits per line. If the player places the maximum wager of 200 credits, a final, forty-first “bonus” line is enabled. The forty-one pay lines are illustrated in  FIGS. 11   a - nn.    
     As shown in  FIG. 8 , the seventh reel  10   g  is a barn symbol, which, in this embodiment, is a cascade-trigger symbol. During the wagering game, if the cascade-trigger symbol appears on an active pay line (a pay line on which the player has placed a wager), the reel disappears ( FIG. 9 ) and one of the reels from the line above cascades down into the disappeared reels position ( FIG. 10 ). 
     As shown in  FIG. 8 , the seventh reel  100   g  is a barn symbol, which, in this embodiment, is a cascade-trigger symbol. During the wagering game, if the cascade-trigger symbol appears on an active pay line (a pay line on which the player has placed a wager), the reel disappears ( FIG. 9 ) and one of the reels from the row above the disappeared reel cascades down into the disappeared reel&#39;s position ( FIG. 10 ). 
     As shown in  FIGS. 8-10 , the barn in the seventh reel  100   g  disappears and the second reel  100   b  cascades down into the position vacated by the seventh reel  100   g . A new reel  100   p  also drops into the position vacated by the second reel  10   b.    
     In this embodiment, the reels cascade in a generally downward direction. As shown in  FIG. 9 , because adjacent rows of reels are offset from each other by one-half reel position, there is not a reel that is directly above the seventh reel  100   g . Instead, the second reel  100   b  and the third reel  100   c  are both above and diagonally adjacent to the cascade-trigger reel  100   g . In order to determine which of the two reels  100   b ,  100   c  should cascade, the gaming machine  10  (or system controller) reviews the tilt of the symbols in the two adjacent reels  100   b ,  100   c . Whichever reel  100   b ,  100   c  includes a symbol that tilts toward the cascade-triggering reel  100   g  is the reel that cascades down into the disappeared reel&#39;s position. If neither (or both) of the symbols tilts toward the cascade-triggering reel  100   g , then the gaming machine  10  (or system controller) may randomly determine which reel cascades. Alternatively, certain symbols (or reels) may be weighted over others, and those may cascade. In other embodiments, the symbol which would create the most winning combinations for the player would cascade. 
     Although in the above embodiment, it is the tilt of the cascading reel that determines which reel cascades, in other embodiments, it may be the tilt of the symbol in the cascade-triggering reel  100   g  that determines the direction of the cascade. In other embodiments, the determination may be completely random, determined by a weighted system, determined by an arrow located on either the cascading reel or cascade-triggering reel, or based upon whichever symbol would generate the most winning combinations or highest pay outs. 
     After the reels have cascaded into place, as shown in  FIG. 10 , the new symbol combinations are again evaluated for winning combinations. If a cascade-triggering symbol appears in any of the reels, then a new cascade begins. Alternatively, the second cascade may be triggered by a winning combination. In such an embodiment, all of the symbols involved in the winning combination would disappear, and a new cascade would occur. As described above, any payouts resulting from a cascade may be multiplied by permitting a player to select one of the spaceships. 
     After the reels have cascaded into place, as shown in  FIG. 10 , the new symbol combinations are again evaluated for winning combinations. If a cascade-triggering symbol appears in any of the reels, then a new cascade begins. Alternatively, the second cascade may be triggered by a winning combination. In such an embodiment, all of the symbols involved in the winning combination would disappear, and a new cascade would occur. 
     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.