Gaming machine with adjustable return to player

Abstract

A method for use with a gaming machine that is arranged to provide a game including displaying symbols on a display and awarding an award if a winning outcome occurs. The gaming machine operates to have an overall statistical return, which is influenced by a pay characteristic. The method includes, prior to determining the outcome of a game play of the game, allocating to that game play one of a plurality of different said pay characteristics, wherein if a first said pay characteristic was permanently the allocated characteristic, the game would have a first statistical return less than the overall statistical return, and if a second said pay characteristic was permanently the allocated characteristic, the game would have a second statistical return greater than the overall statistical return. The method includes allocating the plurality of different pay characteristics to game plays according to a weighted random selection process so as to result in the gaming machine having the overall statistical return.

1 . A method for use with a gaming machine that is arranged to provide a game including displaying symbols on a display and awarding an award if a winning outcome occurs, the gaming machine operating to have an overall statistical return, which is influenced by a pay characteristic, wherein the method includes, prior to determining the outcome of a game play of the game, allocating to that game play one of a plurality of different said pay characteristics,
 wherein if a first said pay characteristic was permanently the allocated characteristic, the game would have a first statistical return less than the overall statistical return, and if a second said pay characteristic was permanently the allocated characteristic, the game would have a second statistical return greater than the overall statistical return, and   wherein the method includes allocating the plurality of different pay characteristics to game plays according to a weighted random selection process so as to result in the gaming machine having the overall statistical return.   
     
     
         2 . The method of  claim 1 , wherein one outcome of the game is the award of a certain number of free game plays of the game and wherein the first pay characteristic is the award of a first number of free games on the occurrence of that outcome and the second pay characteristic is the award of a second number of free games on the occurrence of that outcome. 
     
     
         3 . The method of  claim 2 , wherein the allocation is made before commencement of the game play. 
     
     
         4 . The method of  claim 2 , wherein the allocation is made after it has been determined that said outcome will occur. 
     
     
         5 . The method of  claim 1 , wherein the first pay characteristic is the random selection of symbols from a first symbol set and the second pay characteristic is the random selection of symbols from a second symbol set. 
     
     
         6 . The method of  claim 5 , wherein the game is a spinning reel game and the first symbol set is a first reel and a second symbol set is a second reel and the weighted random selection process includes selecting the first or the second reel for use in the game. 
     
     
         7 . The method of  claim 6 , wherein the weighted selection process selects between only the first reel and the second reel. 
     
     
         8 . The method of  claim 6 , wherein weighted selection process selects between three or more alternative reels. 
     
     
         9 . The method of  claim 5 , wherein the game is a spinning reel game and the first symbol set is a first reel strip portion of a combined reel of the game and a second symbol set is a second reel strip portion of the combined reel, wherein the first and second reel strip portions consist of alternate implementations of the game with different statistical returns, and wherein the number of first and second reel strip portions are provided in proportion to result in said overall statistical return so that the weighted random selection process includes selecting the stopping position of the combined reel. 
     
     
         10 . The method of  claim 1 , wherein the first pay characteristic and the second pay characteristic are selected from the group comprising:
 alternative symbol sets in the game provided in proportion so as to result in the overall statistical return;   alternative awards in the game provided in proportion so as to result in the overall statistical return;   alternative trigger event probabilities provided in proportion so as to result in the overall statistical return; and   alternative award multipliers, provided in proportion so as to result in the overall statistical return,   
     
     
         11 . The method of  claim 10 , wherein the first and second pay characteristics are of the same type and differ only as to their magnitude. 
     
     
         12 . The method of  claim 10 , wherein the first and second pay characteristics operate only in a base game of the game. 
     
     
         13 . The method of  claim 12 , wherein the game includes a feature game. 
     
     
         14 . The method of  claim 10 , wherein the first and second pay characteristics operate only in a feature game of the game. 
     
     
         15 . The method of  claim 1 , wherein the allocation for a game play is independent of the allocation for any other game play. 
     
     
         16 . A method for use with a gaming machine that is arranged to display symbols on a display and award an award if a winning outcome occurs, the gaming machine operating in accordance with an overall statistical return to player, the gaming machine provided with a plurality of symbol sets including at least a first symbol set and a second symbol set, the first symbol set having a first associated return to player value and the second symbol set having a second associated return to player, wherein the first associated return to player value is less than the overall statistical return to player, and the second associated return to player value is greater than the overall statistical return to player, wherein
 the method includes selecting between the plurality of symbol sets for display on the display, wherein the selection is a weighted random selection process that results in the game having the overall statistical return to player.   
     
     
         17 . The method according to  claim 16 , wherein during each play of the gaming machine the gaming machine randomly select symbols from the selected symbol set for display on the display. 
     
     
         18 . The method according to  claim 16 , wherein the gaming machine is a reel type gaming machine and the display includes a plurality of reel strip display positions, and wherein each symbol set includes symbols arranged into a plurality of reel strips, the plurality of reel strips corresponding respectively to the plurality of reel strip display positions. 
     
     
         19 . The method according to  claim 18 , wherein the first symbol set and second symbol set differ from each other only in respect of a single reel strip. 
     
     
         20 . The method according to  claim 16 , wherein the plurality of symbol sets differ from each other by at least one characteristic selected from the group of a symbol type and a bonus associated with the set of symbols. 
     
     
         21 . The method of  claim 1 , wherein in the weighted random selection process the probability of selecting the first pay characteristic is calculated according to the formula:
     p 1=( S−R 2)/( R 1− R 2)   and the probability of selecting the second pay characteristic is calculated according to the formula:
     p 2=(1 −p 1), where: 
   
       p1= the probability of selecting the first pay characteristic set in the weighted random selection process; 
       p2= the probability of selecting the second pay characteristic in the weighted random selection process; 
       S=the overall statistical return to player value; 
       R1= the statistical return associated with the first pay characteristic; 
       R2= the statistical return associated with the second pay characteristic; and 
       R1≦S≦R2. 
     
     
         22 . The method of  claim 16 , wherein in the weighted random selection process the probability of selecting the first symbol set is calculated according to the formula:
     p 1=( S−R 2)/( R 1− R 2)   
       and the probability of selecting the second symbol set is calculated according to the formula:
     p 2=(1 −p 1), where: 
 
       p1= the probability of selecting the first symbol set in the weighted random selection process; 
       p2= the probability of selecting the second symbol set in the weighted random selection process; 
       S=the overall statistical return to player value; 
       R1= the first associated return to player value; 
       R2= the second associated return to player value; and 
       R1≦S≦R2. 
     
     
         23 . A gaming machine that provides a game based on a wager, the gaming machine comprising a user interface in communication with a game controller, the game controller adapted to implement a method for use with the gaming machine that is arranged to provide a game including displaying symbols on a display and awarding an award if a winning outcome occurs, the gaming machine operating to have an overall statistical return, which is influenced by a pay characteristic, wherein the method includes, prior to determining the outcome of a game play of the game, allocating to that game play one of a plurality of different said pay characteristics,
 wherein if a first said pay characteristic was permanently the allocated characteristic, the game would have a first statistical return less than the overall statistical return, and if a second said pay characteristic was permanently the allocated characteristic, the game would have a second statistical return greater than the overall statistical return, and   wherein the method includes allocating the plurality of different pay characteristics to game plays according to a weighted random selection process so as to result in the gaming machine having the overall statistical return.   
     
     
         24 . A gaming machine that provides a game based on a wager, the gaming machine comprising a user interface in communication with a game controller, the game controller adapted to implement a method for use with the gaming machine that is arranged to display symbols on a display and award an award if a winning outcome occurs, the gaming machine operating in accordance with an overall statistical return to player, the gaming machine provided with a plurality of symbol sets including at least a first symbol set and a second symbol set, the first symbol set having a first associated return to player value and the second symbol set having a second associated return to player, wherein the first associated return to player value is less than the overall statistical return to player, and the second associated return to player value is greater than the overall statistical return to player, wherein
 the method includes selecting between the plurality of symbol sets for display on the display, wherein the selection is a weighted random selection process that results in the game having the overall statistical return to player.   
     
     
         25 . An article of manufacture comprising:
 a computer readable storage medium; and   executable program instructions embodied in the computer readable storage medium that when executed by a programmable system cause the system to perform functions that implement a method for use with the gaming machine that is arranged to provide a game including displaying symbols on a display and awarding an award if a winning outcome occurs, the gaming machine operating to have an overall statistical return, which is influenced by a pay characteristic, wherein the method includes, prior to determining the outcome of a game play of the game, allocating to that game play one of a plurality of different said pay characteristics,   wherein if a first said pay characteristic was permanently the allocated characteristic, the game would have a first statistical return less than the overall statistical return, and if a second said pay characteristic was permanently the allocated characteristic, the game would have a second statistical return greater than the overall statistical return, and   wherein the method includes allocating the plurality of different pay characteristics to game plays according to a weighted random selection process so as to result in the gaming machine having the overall statistical return.   
     
     
         26 . An article of manufacture comprising:
 a computer readable storage medium; and   executable program instructions embodied in the computer readable storage medium that when executed by a programmable system cause the system to perform functions that implement a method for use with the gaming machine that is arranged to display symbols on a display and award an award if a winning outcome occurs, the gaming machine operating in accordance with an overall statistical return to player, the gaming machine provided with a plurality of symbol sets including at least a first symbol set and a second symbol set, the first symbol set having a first associated return to player value and the second symbol set having a second associated return to player, wherein the first associated return to player value is less than the overall statistical return to player, and the second associated return to player value is greater than the overall statistical return to player, wherein   the method includes selecting between the plurality of symbol sets for display on the display, wherein the selection is a weighted random selection process that results in the game having the overall statistical return to player.