A method of operating slot machines permits a machine to be identified as available for team play. Upon being identified for team play, the machine is grouped with other slot machines and subject to bonus conditions dependent on the team play. Bonus conditions typically including selected bonus outcomes and a bonus time period, during which bonus time period all outcomes of the grouped machines are monitored to determine the total bonus outcomes. If the total bonus outcomes of the team meet the bonus conditions within the bonus time period, then a bonus payout is awarded to all of the players. Players are thus encouraged to participate in a social, team environment with others of the team to win the group bonus. The invention is applicable to all slot machines, including video poker machines wherein the bonus outcomes include selected video poker hand ranks, and reeled slot machines wherein the bonus outcomes include selected reel outcomes.