Patent ID: 8328627

Claim:
A gaming machine comprising, a display and a game controller arranged to control images of symbols displayed on the display, the game controller arranged to, once a player has staked a wager, play a first game in which at least one random game outcome is displayed on the display, the game controller further arranged to control the award of a prize if the at least one random game outcome corresponds to a winning outcome; the game controller being further arranged to award a plurality of second games upon the occurrence of a trigger event, each of the plurality of second games having a plurality of possible second game outcomes; the gaming machine further comprising a selector that is arranged to allow the player to specify a game credit amount needed to be rewarded from play of the plurality of second games to obtain the award of a bonus amount; the game controller being arranged to control the award of the bonus amount when the number of game credits rewarded from play of the plurality of second games satisfies a criterion that is based on the specified game credit amount; wherein the bonus amount has a value that is based on a probability of the game credits rewarded from play of the plurality of second games meeting the criterion, the probability of meeting the criterion decreasing as the game credit amount specified by the player increases such that winning the bonus amount is more difficult, the bonus amount having a higher value in compensation for such a decrease in the probability of meeting the criterion.