A gaming machine comprises memory storing a pay table comprising a plurality of pay table items, each item defining a prize and a required winning combination of symbols to achieve the respective prize, a pay table modifier configured to modify the pay table to apply to at least one game outcome by changing the required winning combination of symbols associated with a first prize such that a lower number of symbols are required to achieve the first prize, an outcome generator configured to generate each at least one game outcome by selecting symbols for display in a plurality of columns of symbol display positions on a display of the gaming machine, and an outcome evaluator configured to evaluate the selected symbols based on the modified pay table upon the pay table being modified.