Wagering game with time-based bonus

A gaming system for playing a wagering game includes a display and a controller. The display displays a base game of the wagering game in response to receiving a wager input from a player. The controller is coupled to the display and, in response to receiving the wager input, is programmed to increment eligibility time to a counter of bonus-time eligibility. The counter is decremented as real time progresses. If the counter is greater than zero when a bonus game of the wagering game is triggered, the player is allowed to play the bonus game.