Win control method and apparatus for game machines

Abstract

A game machine has a win judgment table. The table stores win information corresponding to each integer in a range of integers. An integers assigned to one special win paying the largest prize is located at the end of the range of integers. In the first game of a win cycle, one integer is randomly selected from the range of integers, and the win information corresponding to this integer is used to determine the outcome of the first game. In each subsequent game of said win cycle, the integer used to determine the outcome of the previous game is incremented and the resulting integer used for the current game. When the end of the integer range is reached, the special win occurs, and the next game becomes the first game of a new win cycle. It is thus assured that the special win occurs in each cycle of games, and that the number of games between special wins never exceeds a certain value.BACKGROUND OF THE INVENTIONThe present invention relates to a win control method and apparatus for a game machine, and more particularly to a method and an apparatus capable of generating a special win with an ensured frequency.A typical such game machine is a slot machine and the present invention will be described and illustrated by way of example in connection with a slot machine; but it is to be understood that the invention is applicable to other game machines as well.Slot machines are so designed that, when a start lever is operated after a coin or coins have been inserted, a plurality of reels, for example three reels, are rotated simultaneously. After the reels have reached a steady angular velocity, the reels can be controlled to stop. In a manually stopped type of machine, the reels are separately stopped by operating corresponding stop buttons. In an automatically stopped type of machine, the reels are stopped one after another by an automatic stop mechanism. If the symbol combination consisting of three symbols arranged on a prize-winning line after the reels have stopped is a winning symbol combination, a prize corresponding to the rank of that particular win is awarded to the player. Among the winning symbol combinations, a combination e.g. of triple "7", i.e., 7-7-7 is the special win, in other words, the so-called big win or big hit, and the most valuable prize is awarded to the player for it. Taking into consideration the paying ratio, win control is performed according to probabilities, so that the big win occurs only once in one cycle of games (for example, a cycle constituted by 4096 games).In order to control winning, a table (win judgment table) is provided for indicating whether or not there is to be a win with respect to each random number and if so, the rank of that win. Sampling is carried out for each game and a judgment as to whether there is to be a win among the sampled random numbers is made with reference to the win judgment table. Therefore, although the big win should occur once during one cycle of games in terms of probabilities, it is in fact possible that no big win might occur during several cycles. If this should occur, the players' enthusiasm or interest in the game would be lost.There is also a video type of slot machine, in which reels are simulated so as to display rows of symbols on a CRT. The above problem is the same in this type of machine; and so the present invention is equally applicable to both slot machines with reels and slot machines with a CRT display.OBJECT OF THE INVENTIONThe object of the present invention is to provide a win control method and apparatus for a game machine, in which a special win necessarily occurs in one cycle of games.SUMMARY OF THE INVENTIONTo achieve the above and other objects and advantages, the present invention provides a win judgment table in which a special win is allotted or assigned to a numerical value at the end of a series of numerical values or to a numerical value in the vicinity thereof. A numerical value included in the series of numerical values is sampled at random only for the first game, and a win judgment is made based on such sampled numerical value in the first game. The game is controlled in accordance with the result of this judgment. In a second game and in the games thereafter, the sampled numerical value is used as an initial numerical value and the win judgment is made using a numerical value (prearranged or predetermined numerical value) specified by the number of times the game has been played. This prearranged numerical value varies in such a manner as to be shifted toward the end of the series of numerical values including the numerical value of the special win. When the prearranged numerical value has reached the end of the series of numerical values as a result of a large number of games having been played, one cycle of games is over. The next game is the first game of the next cycle and numerical values are sampled at random again.In a preferred embodiment of the present invention, the series of numerical values is a series of integers including the minimum numerical value M and the maximum numerical value N, and the special win is assigned to the maximum numerical value N. In a second game and in games thereafter, such sampled numerical value is used as an initial numerical value, and numerical values which have been shifted one by one toward the maximum numerical value N become the prearranged numerical values for such games.According to the present invention, sine all numerical values included in the full range of the series of numerical values are used for the win control, a special win will occur in one game cycle without fail.

Description

Claims

1. A win control apparatus for a game machine, said game machine allowing repeated play of a game, said game having at least one type of winning outcome for which one of at least one type of prize is awarded, said at least one type of winning outcome including a special win for which the most valuable prize is awarded, said win control apparatus comprising:

win judgment table means for storing win information corresponding to each numerical value in an ordered, finite set of numerical values, said win information comprising the type of winning outcome, if any, corresponding to each said numerical value, a first numerical value at one end of said set corresponding to said special win;

sampling means for randomly selecting a numerical value from said set of numerical values;

numerical value shifting means for receiving a numerical value in said set of numerical values and, based on said received numerical value, selecting a different numerical value in said set closer to said one end of said set than said received numerical value;

win judgment means for determining the outcome of a game played on said game machine,

said win judgment means, during a first game or during a game following a game whose outcome was said special win, using said sampling means to randomly select an initial numerical value, further using said win judgment table means to access the win information corresponding to said initial numerical value, and further providing said accessed win information as said game outcome;

said win judgment means, during any other game, using said shifting means to select a current numerical value based on the numerical value used in the previous game, further using said win judgment table means to access the win information corresponding to said current numerical value, and further providing said win information corresponding to said current numerical value as said game outcome;

means for executing a game on said game machine in accordance with said game outcome provided by said win judgment means.

2. A win control apparatus as claimed in claim 1, wherein said set of numerical values is a range of consecutive integers from "M" to "N" and said first numerical value is "M" or "N", where "M" and "N" each represent an integer such that "M"<"N".

3. A win control apparatus as claimed in claim 2, wherein said first numerical value is "N", and said numerical value shifting means increments said received numerical value by one to obtain said different numerical value.

4. A win control apparatus as claimed in claim 2, wherein said first numerical value is "M", and said numerical value shifting means decrements said received numerical value by one to obtain said different numerical value.

5. A win control apparatus as claimed in claim 2, wherein said game machine includes a non-collinear plurality of movable rows of symbols, wherein said outcome of a game played on said game machine comprises a combination of said symbols stopped on a prize-winning line transverse to said symbol rows, and wherein said game execution means controls the stopped position of each said symbol row such that a game outcome determined by said win judgment means is realized.

6. A win control apparatus for game machine as claimed in claim 5, wherein said symbol rows are borne on peripheries of respective reels, said respective reels being rotated by respective pulse motors.

7. A win control apparatus as claimed in claim 6, wherein said game machine further includes manual stop means for stopping rotation of said reels by said respective pulse motors.

8. A win control apparatus as claimed in claim 1, wherein said at least one type of winning outcome comprises a plurality of types of winning outcomes, said at least one type of prize comprises a plurality of types of prizes, each said prize comprises a quantity of coins, and said types of prizes differ from one another in said quantity.

9. A win control method for a game machine, said game machine allowing repeated play of a game, said game having at least one type of winning outcome for which one of at least one type of prize is awarded, said at least one type of winning outcome including a special win for which the most valuable prize is awarded, said win control method comprising the steps of:

storing in a win judgment table win information corresponding to each numerical value in an ordered, finite set of numerical values, said win information comprising the type of winning outcome, if any, corresponding to each said numerical value, a first numerical value at one end of said set corresponding to said special win;

determining the outcome of a game played on said game machine by selecting a numerical value from said set of numerical values, accessing from said win judgment table the win information corresponding to said selected numerical value, and using said accessed win information as said outcome, said selected numerical value, for a first game or for a game following a game whose outcome was said special win, being randomly selected from said set of numerical values, and for any other game, being selected to be closer to said one end of said set than the selected numerical value of the previous game; and

executing a game played on said game machine according to said determined outcome.

10. A win control method as claimed in claim 9, wherein said game machine includes a non-collinear plurality of movable rows of symbols, wherein said outcome of a game played on said game machine comprises a combination of said symbols stopped on a prize-winning line transverse to said symbol rows, and wherein said step of executing a game comprises controlling the position of each said symbol row such that a game outcome determined by said game outcome determination step is realized.

11. A win control method as claimed in claim 10, wherein said symbol rows are borne on peripheries of respective reels, said respective reels being rotated by respective pulse motors.

12. A win control method as claimed in claim 9, wherein said set of numerical values is a range of consecutive integers from "M" to "N" and said first numerical value is "M" or "N", where "M" and "N" each represent an integer such that "M"<"N".

13. A win control method as claimed in claim 12, wherein said first numerical value is "N", and said numerical value selection for said any other game comprises incrementing said selected numerical value from the previous game by one.

14. A win control method as claimed in claim 12, wherein said first numerical value is "M", and said numerical value selection for said any other game comprises decrementing said selected numerical value from the previous game by one.