In football, what's the difference between legal and illegal motion?

Answer by  triberocks (62)

Legal motion, in the NFL, is when only one player is moving parallel or away from the line of scrimmage when the ball is snapped. Illegal motion is when either more than one player is in motion or the player in motion is moving toward the line of scrimmage, when the ball is snapped.

Answer by  brett29 (467)

Certain players can move and others can not. The line can not move but receivers, running backs, and quarterbacks can move.