Abstract:
A gaming machine such as a slot machine is provided having a payout proportional to a wager value. The gaming machine provides a player with the ability to flexibly and automatically increase and decrease wagers, thereby allowing the player to press his bets when he feels lucky, and to decrease his bets when he feels unlucky. Different proportional payout tables are provided for different levels of wagers.

Description:
This application is a continuation of U.S. patent application Ser. No. 08/947,243 filed Oct. 8, 1997 in the name of Walker et al., and titled “GAMING METHOD AND APPARATUS HAVING A PROPORTIONAL PAYOUT.”; which issued as U.S. Pat. No. 6,213,877 on Apr. 10, 2001. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to gaming apparatus and more particularly to gaming apparatus such as slot machines having proportional payout capabilities. 
     BACKGROUND OF THE INVENTION 
     Slot machines generate greater than ten billion dollars per year in revenue for US casinos, with individual machines typically earning between fifty and one hundred and fifty dollars per day. Despite their popularity, however, slot machines offer players a somewhat limited selection of strategies in comparison to other casino games. 
     More specifically, table game players, such as blackjack players, have the opportunity to ‘press’ or increase their bets when they feel lucky, and to reduce their bets when they feel unlucky. No comparable option is readily available to the slot player. 
     While a slot player may reduce a bet by reducing the number of coins played, this option often results in his being excluded from the opportunity to win the top jackpot. In order to significantly increase his bet, a player typically would have to move to a higher denomination machine, a very undesirable option requiring him to leave his lucky, or ‘hot’ machine. While a player may have the option to increase the number of coins bet, the range of bets on typical machines is very limited—often from one to three coins. 
     Thus, it would be very desirable to provide a slot machine which offers to players the ability to press or increase their bets when they are winning. It would be further desirable to offer such a machine which enables players to limit their losses when they are losing. Such a machine could result in the increase of both the total play and the wagered amount of the players. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a gaming apparatus such as a slot machine which provides payouts which are a proportion of the amount wagered. 
     In accordance with one aspect of the present invention, a gaming method and apparatus having a proportional payout are provided, the apparatus comprising a processor and a memory connected to the processor. The memory stores a series of outcomes, and at least one proportional payout multiplier corresponding to an outcome of the series of outcomes. The processor is operative to select from the series of outcomes a resulting outcome, select a resulting proportional payout multiplier corresponding to the resulting outcome, and determine a game result based on the resulting proportional payout multiplier. 
     In accordance with another aspect of the invention, a gaming method and apparatus having a proportional payout are provided, the apparatus comprising a processor and a memory connected to the processor. The memory stores a series of outcomes, and a series of proportional payout multipliers each corresponding to an outcome of the series of outcomes. The processor is operative to receive an initiation signal to initiate a game play, receive a wager signal indicating a wager amount for the game play, and receive a random number for the game play. The processor is further operative to select from the series of outcomes a resulting outcome, the resulting outcome based on the random number, to select from the series of proportional payout multipliers a resulting proportional payout multiplier corresponding to the resulting outcome, and apply the resulting proportional payout multiplier to calculate a resulting payout. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     These and other objects, features and advantages of the invention will be understood from a consideration of the following description of the invention, in which: 
     FIG. 1 is a block diagram of a slot machine constructed in accordance with the present invention; 
     FIG. 2 is a table showing components of the probability table of FIG. 1; 
     FIG. 3 is a table showing components of one embodiment of a proportional payout table; 
     FIG. 3A is a table showing components of the embodiment of the proportional payout table of FIG. 1; 
     FIG. 4 is a table showing components of another embodiment of a proportional payout table; 
     FIG. 5 is a table showing components of yet another embodiment of a proportional payout table; 
     FIG. 6 is a plan view of a slot machine constructed in accordance with the present invention; 
     FIG. 7 is an enlarged view of the payout table of FIG. 6; 
     FIG. 8 is a block diagram of a network of slot machines in accordance with an embodiment of the invention; and 
     FIGS. 9 &amp; 10 together comprise a flowchart illustrating a method of operating a slot machine in accordance with the present embodiment. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Description of the System 
     In accordance with the present invention there is provided herein a gaming method and apparatus, illustrated by way of a slot machine, having a proportional payout table used to determine payouts constituting a proportion of the amount wagered. 
     As used herein, the term “slot machine” means all gaming machines wherein a paid play generates a random or pseudo-random outcome used to determine a payout, including slot machines, video poker, keno, bingo, video roulette, video blackjack, etc. 
     Referring now to FIG. 1, there is shown a block diagram of a slot machine  100  including a central processing unit (CPU)  102  and a data storage device  104  connected to the CPU. Further connected to CPU  102  are: a slot network interface  106 , a starting controller  108 , a random number generator  112 , an input/output (I/O) device  114 , a reel controller  116 , a video display  118 , a hopper controller  122 , and a coin acceptor  124 . 
     Slot machine  100  comprises conventional components, with the exception of a proportional payout table  129  contained in storage device  104 . As will be described in detail below, proportional payout table  129  functions to determine the payout of the slot machine in accordance with the present invention. For purposes of better illustrating the invention, standard components, well known to those skilled in the art, are described only briefly. Although the present embodiment of the invention is described as implemented with physical components, the invention applies equally well to and includes software embodiments such as would be implemented on the Internet and other computer data networks. 
     Referring again to CPU  102 , the device comprises one of many well known processing units, for example a Pentium class CPU manufactured by Intel Corp. Data storage device  104  comprises an appropriate combination of magnetic and optical memory, such as disk drive memory, and semiconductor memory such as random access memory (RAM) and read only memory (ROM). In addition to proportional payout table  129 , data storage device  104  stores a probability table  126  and appropriate operating system and control software (not shown), functional to operate slot machine  100  in the manner described below. Random number generator  112  comprises one of many well known random or pseudo-random number generators suitable for use in a gaming device. As will be further described below, during game play, data storage device  104  also stores a player credit balance. Because generated payouts may be in fractional form in addition to increments of whole coins, storage of a player credit balance includes decimal amounts. 
     Coin acceptor  124  is operative to receive one or more coins, and to transmit an appropriate value signal to CPU  102 . Hopper controller  122 , and hopper  130  connected thereto, are operative under the control of CPU  102  to dispense and output coins to a player. In one embodiment, all partial coin amounts are rounded to the nearest whole coin. Reel controller  116  is operative to control the spin and outcome displayed by first, second, and third reels  132 ,  134 ,  136 , respectively, which may be mechanical in nature, or graphical and displayed on video display  118 . In the present embodiment, slot machine  100  comprises a “22 stop” machine, such that 22 indicia are contained on each of reels  132 ,  134 ,  136 . Video display  118  comprises any appropriate video display apparatus, for example, a cathode ray tube or a liquid crystal display screen. 
     Starting controller  108  comprises a player-operated device such as a handle or button for initiating the play of a game. I/O device  114  comprises a conventional player interface including a card reader  138  for receiving a player tracking card, a display  142  for communicating alpha/numeric messages to the player, and a keypad  140  for receiving player input such as a player identifier. 
     Slot network interface  106  comprises a conventional network interface for connecting slot machine  100  to a centrally controlled network consisting of multiple machines, enabling functions further described below. 
     Referring now to FIG. 2, probability table  126  is seen to include eighteen records indicated at  128   a-r , each record including three fields: a random number field  130 , a combination field  132 , and an expected hits per cycle field (‘hits’ field) 134 . Random number field  130  of each record indicates a range of random numbers, for example record  128   d  indicating a range of random numbers from 9931 through 10130. Combination field  132  indicates a reel indicia combination for each random number range, the combination for record  128   d  comprising “Cherry/Cherry/Any”, the “Any” constituting any reel indicia other than Cherry. Thus, when random number generator  112  generates a random number in the range of 9931 through 10130 for a game play (the details of which are described below), reel controller  116  will control reels  132 ,  134 ,  136  to display the described Cherry/Cherry/Any combination. 
     Continuing with reference to FIG. 2, hits field  134  includes the theoretical number of times a particular random number range and corresponding combination will occur, out of a total of 10,648 plays in a cycle. Thus, with reference again to record  128   d , a random number in the range of 9931 through 10130 will occur, resulting in a Cherry/Cherry/Any combination, two hundred times out of every 10,468 game plays. Each other record  128   a-r  in table  126  is interpreted in a like manner. 
     The selection of the data for probability table  126  is performed in a manner well known to those skilled in the art, and, as will be understood from a consideration of the further explanation below, is performed so as to yield combinations  132  and payouts that make the game enticing to the player while yielding a ‘house advantage’ sufficient to produce a predetermined level of profit for the operator of the slot machine. The contents of table  126  have been selected for the described embodiment of the invention from Regan, Jim,  Winning At Slot Machines,  Carol Publishing Group Edition, 1996. One skilled in the art will recognize the table as conventional for a twenty-two stop machine. 
     Referring now to FIG. 3, one embodiment of a proportional payout table  135  is shown to include eighteen records  136   a-r , each of which includes seven fields: combination and expected hits per cycle fields  132 ,  134 , which are identical to the like-numbered fields from FIG. 2, a pay amount field  138 , a coins paid field  140 , a fixed player win/(loss) field  142 , a proportional payout field  144 , and a proportional player win/(loss) field  146 . 
     Pay Amount field  138 , coins paid field  140 , and fixed player win/(loss) field  142  comprise fields from a conventional prior art slot machine. They are included here for the purpose of illustrating the invention. They are not necessary to the practice of the present invention. 
     More particularly, pay amount field  138  indicates the number of coins paid out on a game play where a random number results in the generation of a particular combination  132 . Coins paid  140  indicates the theoretical number of coins paid out over the cycle of 10,468 plays for each combination  132 , while fixed player win/(loss) field  142  indicates the theoretical player win/(loss) for a given pay combination  132 . Thus, examining record  136   d , with the Cherry/Cherry/Any combination expected to occur 200 times out of a cycle of 10,468 plays, and with a pay amount of 5 coins, then 1000 coins would be paid out over the cycle. Subtracting the 200 coins wagered yields the player win of 800 coins. A slot machine paying out in accordance with pay amount field  138  would provide a house advantage of 5.5%, calculable by dividing the total player loss of 586 coins by the total coins wagered for the cycle of 10,468. Continuing to describe FIG. 3, in lieu of using pay amount field  138  to determine a payout for a given combination, in accordance with the present invention, proportional payout field  144  is used to determine a proportional percentage of the wagered amount to be paid for each given combination. Thus, continuing to examine record  136   d , for the Cherry/Cherry/Any combination, a proportional payout of one-hundred and sixty percent (160%) of the wagered amount will be paid out to the player. For example, a player putting at risk a wager of thirty coins would receive a payout of eighteen coins, bringing his credit balance to forty-eight coins. For the non-winning combination of record  136   a , eighty percent out of the player&#39;s credit balance will remain, resulting in a 20% loss of the amount wagered by the player. 
     Examining proportional player win/(loss) field  146  (which is based on a one coin wager), it can be seen that the total payouts to the players and the total house advantage using applicant&#39;s proportional payout table remain almost the same as those resulting from the use of the fixed pay amount. Thus, as will be described in further detail below, applicant&#39;s slot machine provides players with significantly improved wagering flexibility and options while providing substantially the same player payout and house advantage. 
     With reference now to FIG. 3A, proportional payout table  129  is shown to include eighteen records  137   a-r , each including six fields: combination and expected hits per cycle fields  132 ,  134 , corresponding to the like-numbered fields in FIG. 3, proportional payout and proportional player win/(loss) fields  144 ,  146 , also corresponding to the like-numbered fields in FIG. 3, a second proportional payout field  145 , and a second player win/(loss) field  147 . In comparison to proportional payout table  135  of FIG. 3, proportional payout field  145  has been included to provide increased payouts for wagers greater than a predetermined number of coins/credits: in the embodiment described here, wagers greater than one hundred coins. Proportional player win/(loss) field  147  provides corresponding data for proportional payout field  145 . 
     Thus for wagers of less than one hundred coins, proportional payout field  144  is used to select the appropriate proportional payout. For wagers greater than one hundred coins, a proportional payout is selected from proportional payout field  145 . As will be understood from a consideration of proportional player win/(loss) field  147 , the house advantage is lower for larger wagers having a proportional payout selected from field  145 . Such a lower house advantage is similar to the lower house advantage accepted for slot machines of the prior art: that is, for example, machines of the prior art typically incorporate bonus payouts when maximum coins are played. 
     Turning now to FIG. 4, another proportional payout table  150  is shown including eighteen records  152   a-r , each including four fields: combination and expected hits per cycle fields  132 ,  134 , corresponding to the like-numbered fields in FIG. 3, a proportional payout field  154 , and a player win/(loss) field  156 . In comparison to proportional payout table  135  of FIG. 3, proportional payout field  154  has been modified in record  152   r  to reflect a maximum payout, or jackpot, of a fixed number of 100 coins. The net player profit and house advantage remain substantially the same as when the previous embodiment of the proportional payout table is utilized, thus providing players with a fixed jackpot game option. Higher jackpot payouts can be offered where a lower house advantage is acceptable. In an alternate embodiment of the invention, the higher of either the jackpot or the proportional payout is paid to the player. 
     It should be noted that in embodiments in which fixed payouts are combined with proportional payouts, the house advantage varies depending on the number of coins wagered. In the present embodiment, as more coins are wagered, the house advantage increases because one of the potential payouts to the player (the jackpot for 7-7-7) remains fixed, i.e. does not increase along with the other payouts. Players may perceive a benefit in that the top payout is guaranteed to be a substantial fixed value, regardless of the number of coins wagered. 
     With reference now to FIG. 5, yet another proportional payout table  160  is shown including eighteen records  162   a-r , each including four fields: combination and expected hits per cycle fields  132 ,  134 , corresponding to the like-numbered fields in FIG. 4, a proportional payout field  164 , and a player win/(loss) field  166 . In comparison to proportional payout table  135  of FIG. 3, proportional payout field  164  has been modified in record  162   a  to reflect a fixed loss for each losing play. In the embodiment shown, a player will lose 0.2 coins every losing play, resulting in the loss of one (1) full coin for every five losing plays. 
     In alternate embodiments, the value of the fixed coin loss can be adjusted, and is preferably variable depending on the size of the wager. While a fraction of a coin may be an appropriate loss for wagers of up to several coins, a larger loss is appropriate for larger wagers. For example, an adjustable scale may provide a 20 coin loss for wagers in the 100-200 coin range, and a 30 coin loss for wagers in the 200-300 coin range. As with the alternate embodiment described with respect to FIG. 4 above, the remaining proportional payouts can be adjusted such that the net player loss and house advantage remain substantially the same as that of FIG. 3, thus providing players with a fixed loss game option. 
     Referring now to FIG. 6, a plan view of slot machine  100  is shown which, for purposes of discussion, is generally divided into three sections: an upper panel  200 , a central panel  202 , and a lower panel  204 . Upper panel  200  includes a pay table  206  comprising, for example, painted ‘belly’ glass. The details of pay table  206  are discussed with respect to FIG.  7 . 
     Central panel  202  houses I/O device  114  including card reader  138 , keypad  140 , and display  142  shown set to read “INSERT CARD HERE.” To the left of I/O device  114  is positioned video display area  118 , the display shown as reading a CURRENT CREDIT BALANCE value  208 , a PROPORTIONAL MULTIPLIER value  210 , and a FINAL CREDIT BALANCE value  212 , the details and operation of which are described below. 
     Lower panel  204  is seen to house coin acceptor  124 , starting controller  108  (in the form of a handle), and the display of first reel  132 , second-reel  134 , and third reel  136 . In the described embodiment, the three reels constitute mechanical reels having painted indicia visible through lower panel  204 . In an alternate embodiment, the reels constitute virtual electronic functions with outputs shown on conventional electronic graphical displays, such as LCD displays. 
     With reference now to FIGS. 6 and 7, pay table  206  is seen to include three distinct graphical areas: a first combination table  214 , a proportional multiplier table  216 , and a second combination table  218 . Each combination table represents, in descending order of value, possible outcomes described in combination field  132  of proportional pay table  129 . Multiplier table  216  represents the data stored in the proportional payout fields  144  and  145  of proportional payout table  129 . That is, the proportional payouts in table  216   a  correspond to field  144  of proportional payout table  129  and are available to players wagering less than 100 coins (or credits) on a given play. The higher set  216   b  of proportional payouts correspond to field  145  of proportional payout table  129  and define awards for players wagering more than 100 coins on a game play. As is well known to those skilled in the art, the results of a game play, indicated by the displayed indicia on first, second, and third reels  132 ,  134 ,  136 , are used with the indicia in pay tables  214  and  218  to determine the outcome, or proportional payout from table  216 , of a play. The outcome is determined as a result of the random number generated upon initiation of game play. 
     The inclusion of two sets  216   a  and  216   b  of proportional payouts are intended to motivate players to place larger wagers on game plays. As described above, these two tables  216   a ,  216   b  correspond respectively to the two payout fields  144 ,  145  of proportional payout table  129  (FIG.  3 A). A player depositing 200 coins, for example, is eligible to receive a proportional payout of 1500% for a 7/7/7 outcome, an award which is larger than the 1000% proportional payout available to a player wagering fewer than 100 coins. It will be appreciated that this two-tiered bonus structure is similar to that of bonuses awarded for royal flushes in video poker where maximum coins are wagered. 
     Referring now to FIG. 8, a slot machine network  220  is shown to include four slot machines  100 ,  222 ,  224 ,  226  connected to a slot network server  228  through a slot network interface  230 . Slot machines  222 ,  224 ,  226  may be identical to slot machine  100 , or may comprise completely different machine types, many of which are well known in the art. 
     Slot network server  228  can comprise one of many known servers, for example an RS/6000 manufactured by IBM Corp. Slot network interface  230  likewise comprises a well known combination of computer data links and network interface equipment. In operation, the network of slot machines enables player information to be stored on slot network server  228  and accessed at each slot machine upon the use of a player tracking or identification card in reader  138 . Such central storage of information enables, for example, the storage of player credits, the storage of player-specific information, game results such as handle pulls or coin-in, and the monitoring, control and adjustment of the various connected slot machines. Networking of slot machines has particular application in the present invention in that it enables player credit balances to be stored on and retrieved from slot network server  228 . This enables a player to easily identify a large credit balance with which to wager, taking full advantage of the proportional payout feature of the machine. 
     Description of the Operation 
     Referring now to FIG. 9, a method  300  is shown for operating slot machine  100  in accordance with proportional payout table  129  of FIG.  3 A. The operation of the machine using alternate payout tables  135  (FIG.  3 ),  150  (FIG.  4 ), or  160  (FIG. 5) is substantially identical with the substitution of the alternate proportional payouts. 
     To enable a game play, a player must first establish a credit balance with the slot machine. This can be accomplished by inserting coins into coin acceptor  124  (step  302 ). Alternatively, the credit balance can be established by using a player tracking/identification card that either: 1) includes a credit balance encoded thereon, or 2) references a credit balance stored in slot network server  228  through slot machine network  220 . In all cases, the available player balance is displayed on video display  118  (step  304 ). 
     To initiate a game play, a player operates the starting controller of slot machine  100 , in this case by pulling handle  108  (step  306 ). Responsive to the starting of the game, a random number is obtained from generator  112  (step  308 ). It will be understood that this random number can be generated specifically for the game, or may be selected from a series of random numbers being generated on a consistent or periodic basis by random number generator  112 . Many methods of generating random numbers are well known in the art. 
     Subsequent to the generation of a random number for the game play, that random number is used with probability table  126  to identify the record and hence the combination corresponding to the range of the random number (step  310 ). For example, the random number 9998 would fall in the range designated by record  128   d , identifying the combination Cherry/Cherry/Any. The combination along with the wager value is then used to identify the corresponding field in proportional payout table  129 , in this example field  144  or  145  from record  137   d  (step  312 ). Hence if the wager was less than one hundred coins, then the proportional payout is selected from field  144  to be 160%, while if the wager was greater than one hundred coins the proportional payout is selected from field  145 . While an identical payout results for the present example, it will be seen that different payouts would result for the winning combinations of records  137   q  and  137   r.    
     CPU  102  uses the retrieved payout percentage (step  314 ) with the wager value signal (step  316 ) to calculate a new credit balance (step  318 ). So, for example, assuming that the credit balance showed a wager value of 90 coins, and the game play resulted in a combination of Cherry/Cherry/Any, then from record  137   d  the proportional payout of 160% is used to calculate the new credit balance as follows. Equation 1) shows the generic calculation, while equation 2) shows the actual calculation for the described example: 
     1) starting credit balance×proportional payout=new credit balance, 
     2) 90 coins×1.6=144 coins. 
     Continuing with reference to FIG. 10, the new credit balance is displayed to the player on video display  118  (step  320 ), and stored for future play (step  322 ). 
     Alternate Embodiments of the Invention 
     Alternate proportional payout tables  135 ,  150 , and  160  may be used in lieu of table  129 , with the latter two providing a maximum jackpot, and a fixed value loss, respectively. The operation of the machine would otherwise be identical to that described above. 
     While several different proportional payout tables have been shown and described above, those skilled in the art will recognize that numerous different proportional payout schemes may be implemented in accordance with the present invention. 
     In another embodiment of the invention, the maximum jackpot for machine  100  may be progressive. That is, the jackpot increases in value for each play that a jackpot payout is not awarded. Such progressive jackpots could be applied to proportional payouts by increasing the proportion, and to fixed payouts by increasing the fixed jackpot amount. 
     As mentioned briefly above, slot machine  100  can be altered to provide a player with the ability to vary his bet by selecting for each play some to all of his available credit for wagering. Such a function would be provided by enabling CPU  102  to receive a signal indicating the value of the wager, for example from keypad  140  of I/O device  114 , or from a separate, dedicated input device (not shown). In this embodiment, the proportional payout multiplier is applied to the wager amount, which may vary from the credit balance. 
     In yet another embodiment, a minimum wager may be required in order to make a player eligible for a jackpot payout. Such a minimum wager would be displayed directly on the face of slot machine  100 . 
     SUMMARY 
     There is thus provided a new and improved gaming machine wherein a proportional payout based on a wager value is provided in lieu of a fixed payout amount. The invention enables players to wager large numbers of coins (i.e. to place large bets) on machines typically limited to several coins, thereby permitting the players to increase their bets when they feel lucky. The invention provides many different payout options, including ones where losses are proportionally limited to the wager amount. While the invention has been shown and described with respect to a slot machine, it is not so limited. It has applicability to all of the types of gaming machines described above, and has particular applicability to casino type gambling machines.