Overtime in football is an extra quarter or period of game time to decide the winning team of a football game. Overtie is only used if the score is tied at the end of regulation. High school overtime, college overtime, and NFL overtime rules are different. The coin toss and the coin toss options are different as well. In NFL overtime, quarters last 15 minutes and the ball is put into play with a kickoff. In college football overtime, only the play clock ticks and teams alternate possession starting at the 25-yard line.