A play clock (also called a delay-of-game timer) is a timer designed to increase the pace (and subsequently, the score) in American football and Canadian football, similar to what a shot clock does in basketball. The offensive team must snap the ball before the time expires, or else they will be assessed a 5-yard delay of game penalty. If a visible clock is not available (or not functioning), game officials on the field will use a stopwatch or other similar device to enforce the rule.

In Canadian football, the offensive team must run a play within 20 seconds of the referee whistling the play in; in American football, teams have 25 seconds – except in the National Football League where teams have 40 seconds from the end of the previous play.

In the strategy of clock management, a team can slow the pace of a game by taking the maximum amount of time allotted between plays. A team wishing to do so would wait to snap the ball until there is one second left on the play clock.

American football terminology | Canadian football terminology

All-American delay-of-game timer

Daktronics delay-of-game timer

Electro-Mech football scoreboards

Nevco football scoreboards