5yards

False start

Offense moves before the snap.

What you see. An offensive player moves, the whistle blows, and the ball never moves.
Typical result. 5 yards, and the down is replayed.
Easy mix-up. Offside is the defense. Delay of game is the play clock hitting zero.
On the field. Usually the offensive line. See offense positions and the plays.

The whistle blows before the ball moves.

Yardage is from the 2026 NFL distance lists. Hand signals live in the official signals PDF. Independent fan guide, not a league ruling.