A fifteen-yard penalty given to a player who has committed an act of unnecessary roughness or unsportsmanlike conduct. Personal fouls are assessed after the result of the play, and can be called on either the offense or the defense. A personal foul on the defense results in an automatic first down for the offense. Players can be ejected for a personal foul, but it is not automatic. Personal fouls can be called on both teams on the same play.
The personal foul is considered the most reviled of penalties, and the most avoidable. The two main kinds of personal foul are unnecessary roughness and unsportsmanlike conduct. Examples of unnecessary roughness include a late hit after the conclusion of the play, a grasp of the facemask that turns the head of an opposing player, an illegal block on the knees of an vulnerable player, or a blow to the head of the quarterback. Examples of unsportsmanlike conduct include taunting, excessive celebration after a touchdown, contact with an official, or fighting with an opposing player. In the event that two players from opposing teams receive personal fouls on the same play, the penalties are considered to be "offsetting" and the down is replayed.