Pass interference

In American and Canadian gridiron football, pass interference (PI) is a foul that occurs when a player interferes with an eligible receiver's ability to make a fair attempt to catch a forward pass. Pass interference may include tripping, pushing, pulling, or cutting in front of the receiver, covering the receiver's face, or pulling on the receiver's hands or arms. It does not include catching or batting the ball before it reaches the receiver. Once the ball touches any defensive player or eligible offensive receiver the above rules no longer apply and the defender may tackle the receiver or attempt to prevent him from gaining control of the ball.

Once a forward pass is in the air it is a loose ball and thus any eligible receiver – all defensive players are eligible receivers – may try to catch it. When a defensive player catches a forward pass it is an interception and his team gains possession of the ball. Some actions that are defined as pass interference may be overlooked if the defender is attempting to catch or bat the ball rather than focusing on the receiver.

The intended receiver may find himself a defender if a defensive player has a better chance to catch a forward pass. If an offensive player commits pass interference against a defensive player attempting to intercept a forward pass it is offensive pass interference.

Rules for pass interference differ between American and Canadian football:

In the NFL, the defender may make continuous contact with receiver within the first five yards of the line of scrimmage. Anything after that is penalized as illegal contact. Pass interference is called if the defensive player contacts the offensive player while he is trying to catch the pass, unless the defender has turned his head to face the oncoming pass and is attempting to intercept it. Accidental, glancing contact is not penalized.

In high school and college, the defender may make contact with the receiver as long as the receiver is in front of the defender. These provisions end when the pass is in the air.

If the incident occurred on a special teams fake play, the rule does not apply under NFL rules.

In the NFL and the Canadian Football League the penalty for defensive pass interference is an automatic first down at the spot of the foul. If the foul occurs in the end zone, the ball will be placed at the one-yard line (or half the distance to the goal if the line of scrimmage was already inside the 1 yard line). In U.S. college football and amateur Canadian football, the penalty is to the spot of the foul, up to a maximum of 15 yards from the previous spot, and an automatic first down. In U.S. high school rules the penalty is 15 yards from the previous spot with the down replayed for both offensive and defensive pass interference. Prior to 2013, the penalty for defensive pass interference also included an automatic first down while the penalty for offensive pass interference included a loss of down. In the NFL and CFL, the penalty for an offensive pass interference is 10 yards from the previous spot. In amateur Canadian football, the penalty is 15 yards.

...
Wikipedia