A method for use with a gaming system that provides a game in which a plurality of symbols are selected and presented on a display to form one or more combinations includes: providing a base game, providing a feature game on the occurrence of a first event during play of the base game, awarding a jackpot on the occurrence of a second event during play of the feature game, and varying the probability of both the first and the second events dependent on at least an aspect of a wager placed by a player to play the base game, wherein said variation maintains at least an approximately constant probability of the jackpot being won despite variations in said aspect of the wager.