The invention is a method and a device for adding a bonus prize component to wagering games such as those played in gambling casinos. A player obtaining a predetermined combination in the underlying game wins the bonus prize. This might be a predetermined combination of playing cards in a card game or a predetermined combination on the reels of a slot machine. The bonus prize may require a separate side wager to qualify. The bonus prize is randomly chosen from a group of bonus prizes that includes an incrementing jackpot. The device for practicing the method includes a prize wheel that is spun to randomly choose the bonus prize, and an incrementing device with attached jackpot display for generating and showing the current amount of the incrementing jackpot. Upon winning the incrementing jackpot, the incrementing stops and the player wins the current amount shown on the display. The incrementing jackpot is subsequently reset and the incrementing resumed.