A penalty in football in which an offensive play blocks a defensive player from behind, usually at or below the waist. The penalty is assessed fifteen yards from the previous line of scrimmage. Clipping is one of the penalties created to protect player safety, due to the dangerous nature of blocks from behind on unaware players.
Clipping can be a devastating penalty for an offense due to the large amount of yardage assessed, and due to the avoidable nature of a clipping penalty. Typically, clipping is called when an offensive player flagrantly throws themselves at the back of an opposing player, particularly if contact is made below the waist. Most often, clipping penalties result when an offensive player was late with the block and makes a desperation effort to make a play on the defense. Since the penalty is assessed fifteen yards from the previous line of scrimmage, clipping penalties have a tendency to kill offensive drives.