A gaming reward system is described that guarantees a jackpot to a game player. The jackpot is cumulative and based upon the amount paid in by the player over time to play the game. Each time the player plays, the system adds a small amount of the player's wager to the player's jackpot. Over time, the jackpot grows larger. At some point, a triggering event occurs, and the player is awarded the cumulative, guaranteed jackpot. The jackpot is cumulative in the sense that its amount is increased with each play by the player and guaranteed in the sense that the system works to make sure only the specific player who fills the jackpot can win the jackpot.