Multiple tier random number generator
First Claim
1. A slot machine comprising control means for controlling operation of the machine, display means including a plurality of display positions for displaying combinations of indicia and reward means for returning a reward to a player of the machine in response to certain predetermined indicia combinations being displayed on the display means at the end of a game, the display means including a separate indicia display means for each display position, each indicia display means being responsive to the control means to display an indicium at the end of the game which is selected by the control means from a set of possible indicia, and the control means including indicia selection means for making that selection for each of the display positions, wherein, for at least one display position, a two tier selection process is employed whereby the set of indicia is divided into at least two non-overlapping subsets and the indicia selection means comprises first random number selection means for selecting a random number from a set of random numbers having members each of which uniquely corresponds to one member of a first of said subsets of the set of indicia plus additional members each of which uniquely corresponds to one of the remaining subsets of indicia, and second random number generation means, which is invoked only in the event of the first random number generation means selecting a number corresponding to one of said remaining subsets, the second random number generation means being arranged to select a number from a set of numbers each of which uniquely corresponds to one indicia in said one of said remaining subsets of indicia, and the display means being arranged to display the indicium corresponding to the number generated by the first random number generation means if the random number selected by the first random number generation means is a number corresponding to a member of said first of said subsets, and being arranged to display the indicium corresponding to the number generated by the second random number generation means, if the number selected by the first random number generation means is a number corresponding to one of the remaining subsets.
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Accused Products
Abstract
A slot machine is provided in which the symbols or indicia to be displayed are selected by using a random number generating technique to generate a random number for each display position, the random number being selected from a first range of numbers corresponding to the number of display possiblilities for that position. A two step random number selection technique is used wherein the first step comprises selecting a random number from a second range of numbers corresponding to the number of display possibilities for that display position less one, and the second step, which is only invoked in the event that a predetermined one of the numbers in the second range is selected, comprises selecting between that predetermined number and the number in the first range which is excluded from the second range. Accordingly, the probability of occurrence for two of the possible results for the display position is different to that for the remainder of the possible results.
362 Citations
14 Claims
- 1. A slot machine comprising control means for controlling operation of the machine, display means including a plurality of display positions for displaying combinations of indicia and reward means for returning a reward to a player of the machine in response to certain predetermined indicia combinations being displayed on the display means at the end of a game, the display means including a separate indicia display means for each display position, each indicia display means being responsive to the control means to display an indicium at the end of the game which is selected by the control means from a set of possible indicia, and the control means including indicia selection means for making that selection for each of the display positions, wherein, for at least one display position, a two tier selection process is employed whereby the set of indicia is divided into at least two non-overlapping subsets and the indicia selection means comprises first random number selection means for selecting a random number from a set of random numbers having members each of which uniquely corresponds to one member of a first of said subsets of the set of indicia plus additional members each of which uniquely corresponds to one of the remaining subsets of indicia, and second random number generation means, which is invoked only in the event of the first random number generation means selecting a number corresponding to one of said remaining subsets, the second random number generation means being arranged to select a number from a set of numbers each of which uniquely corresponds to one indicia in said one of said remaining subsets of indicia, and the display means being arranged to display the indicium corresponding to the number generated by the first random number generation means if the random number selected by the first random number generation means is a number corresponding to a member of said first of said subsets, and being arranged to display the indicium corresponding to the number generated by the second random number generation means, if the number selected by the first random number generation means is a number corresponding to one of the remaining subsets.
- 10. A method of selecting an indicium to be displayed in a slot machine display, the method comprising dividing the set of possible indicia into a plurality of subsets, randomly selecting an element from a set of elements each of which uniquely corresponds to one of the number of indicia in a first of the subsets and the number of remaining subsets, and in the event that the selected element corresponds to one of the remaining subsets further randomly selecting an element from another set of elements corresponding in number to the number of indicia in said one of said remaining subsets and displaying the indicium corresponding to the element selected in said first or second selection.
Specification