Rule 3 – Section 3 – Article 2 – Starting and Stopping the Clock

If the margin in the score becomes more than 34 points, a running clock session will start. During a running clock session, the game clock will stop only for reasons marked * below. For other events listed here, the clock will keep running. Competitions may adopt regulations to:

1. forgo the running clock rule completely;
2. forgo the rule only in the first half of a game;
3. limit the running clock rule to use after an elapsed time no later than 2 hours 15 minutes after kickoff, but only in games that are broadcast live;
4. reduce the score margin below 34 points.

…….

d. Starts on the Snap. For each of the following, the game clock is stopped on an official’s signal. If the next play begins with a snap, the game clock will start on the snap:

1. Touchback (provided Team B will next snap the ball).
2. With fewer than two minutes remaining in a half a Team A ball carrier, fumble or backward pass is ruled out of bounds. (Exception: After a Team A forward fumble goes out of bounds, the clock starts on the referee’s signal.)
3. Team B is awarded a first down and will next snap the ball. (A.R. 3-3-2:V)
4. A forward pass is ruled incomplete.
5. A team is granted a charged timeout. *
6. The ball becomes illegal. *
7. A period ends. *
8. A legal kick down ends. (A.R. 3-3-2:VI)
9. A return kick is made.
10. A scrimmage kick is made beyond the neutral zone.
11. Team A commits a delay-of-game foul while in a scrimmage kick formation.