Palpably unfair act

In gridiron football, a palpably unfair act is a case of any illegal action that the officials of a sports game deem has clearly and indisputably deprived a team of a score. It is one of the rarest penalties in the sport.

The definition of a palpably unfair act is deliberately vague and leaves great latitude to the officials in determining what constitutes such an act. It also gives great latitude to the officials in regard to punishment; the National Federation of State High School Associations, for instance, allows for any punishment, up to and including forfeiture of the game. However, the same rulebook also indicates a general principle that all acts are legal unless otherwise prohibited by a specific rule. Thus, the palpably unfair act rule is generally only enforced when the penalty for a particular rule violation is insufficient to offset the effect of the act on the play.

Examples
The following situations can draw a palpably unfair act call:
 * A member of the defensive team coming off the sidelines and interfering with a member of the offensive team in an attempt to score a touchdown (as infamously happened in the 1954 Cotton Bowl Classic)
 * A member of the defense continually charging at the center prior to the snap in order to prevent the offense from snapping the ball
 * Continually calling defensive signals in a manner designed to draw the offense offside
 * The defense commits repeated intentional infractions very close to its own goal line (the half-the-distance rule making the consequence of such infractions otherwise infinitesimal).