Free game bonus round for gaming machines

A system of linked gaming machines is disclosed herein. Upon a certain triggering event occurring, eligible gaming machines simultaneously receive a signal for initiating a free game bonus round. The players that have been playing the gaming machines will then play a certain number of free games in a competition with other players involved in the same bonus round. The player awarded the most credits or points from the play of the free games is awarded a special jackpot. Other jackpot games (e.g., split jackpot) are also envisioned. In another embodiment, a jackpot award or any award to the player may be granted based on a certain outcome of the free games. The possibility of the free game bonus round occurring at any time provides incentive for players to keep playing the linked gaming machines. The free game bonus round may also be played on a single non-linked machine where bonuses may be granted for credits exceeding certain levels. Other features are described, such as the dynamic allocation of percentages of wagers to various jackpots and other pots used in the free game bonus round.