Illegal use of hands is a penalty in Football that is called on a team when a player's hands make contact with an opposing player's face-area intentionally and forcefully, especially above and around the facemask. This penalty is in place to prevent head and neck injuries of players, especially offensive linemen who are constantly blocking against defenders rushing into them. This penalty is most often incurred by offensive players. If this penalty is incurred by an offensive player, the offense is penalized 10 yards. If performed by a defensive player, the defense is penalized 5 yards and the offense is awarded an automatic 1st down.
Most of the time this penalty is called, it is due to offensive linemen attempting to block defenders coming around the edge of the line of scrimmage. The linemen attempt to grab onto the defenders, but often make contact with the facemask.