A method for providing a jackpot controlled by a computer implemented jackpot controller. The method includes (a) on commencement of the jackpot, the jackpot controller setting a start-up jackpot prize value, the start-up prize value being the sum of a base amount and a predefined average increment amount for the jackpot, (b) incrementing the jackpot prize value by the jackpot controller using contributions from at least one participating gaming device until a jackpot trigger is determined; and (c) in response to the jackpot controller determining the jackpot trigger, awarding the jackpot prize and re-setting the jackpot prize value to the base amount.