Patent ID: 7883407

Claim:
A method of operating a gaming system, said method comprising: (a) for each of a plurality of plays of a primary game of a first gaming machine: (i) enabling a player to wager one of a plurality of different wager amounts on said play of the primary game, and (i) for said play of the primary game: (A) randomly determining a primary game outcome, (B) causing a display device to display the randomly determined primary game outcome, (C) determining a primary game award, said determined primary game award based on the determined primary game outcome and which of the plurality of different wager amounts was wagered on, and (D) causing the display device to display the determined primary game award; (b) separate from determining any primary game awards: (i) determining a probability of the first gaming machine awarding a prize, said being: (A) dependent upon at least a plurality of, but not all of the amounts wagered on that first gaming machine during an elapsed period, and (B) determined regardless of any amounts wagered at any other gaming machine, and (ii) determining whether to award the prize, said determination based on the determined probability; and (c) if the determination is to award the prize to the player: (i) causing the display device to display the prize, and (ii) providing the prize to the player playing the first gaming machine when the determination is to award the prize to the player.