Kickoff (gridiron football)

Additionally, penalties exist for various infractions such as a player violating his position restrictions prior to the kick (5-yard penalty), or if the ball goes out of bounds before touching a player (25 yards past the spot of the kick or placed at the spot the ball left the field of play, whichever is more advantageous to the receiving team).

A kickoff occurs at the start of each half and before the first overtime (in the National and Arena Football Leagues).

An exception to the Canadian rule applies in U Sports competition; if a team scores a field goal on a play that began after the three-minute warning in the fourth quarter, a kickoff is mandatory, with the scoring team kicking off from the standard position of its own 45-yard line.

In American football (but not Canadian) touchback and fair catch rules apply to the kicked ball.

It is usually done when a team takes the lead in the final seconds, and is done to safely run out the remainder of the clock.

Squib kicking with more than 20 seconds remaining has had unfortunate results (a line drive kick is more common when there are 20 to 50 seconds remaining; the typical hurry-up offense drive takes over a minute), but has been done by some teams.

The XFL also had severe penalties for kicks that went out of bounds, or fell short of the receiving team's 20-yard line.

[6] If a receiving player crosses his restraining line before the kick, the ball is to be advanced 5 yards, then re-kicked.

The XFL had distinctive penalties for kicks that went out of bounds, failed to reach the receiving team's 20-yard line in flight, or returned behind the 20 after touching the ground past it.

Kickoffs entering the end zone are handled differently in American and Canadian rules.

In the Canadian game if the ball goes into the end zone and then out of bounds without being touched, the receiving team scrimmages from the 25-yard line (no points are scored).

Various forms of indoor football also recognize the single, but the ball must not only cross the end zone but pass through the uprights (as in a field goal) as well.

If the kicking team recovers its own kickoff in the end zone in any version of the game (something that, as previously mentioned, is impossible in high school football outside of Texas), it scores a touchdown.

[8] Under standard rules (i.e., those in leagues other than the NFL), to receive a kickoff and set up a kickoff return, the receiving team sets up its players starting from 10 yards back from the point the ball is kicked from.

There are usually one or two players positioned deep (around the goal line) that will attempt to catch or pick up the ball after it is kicked off by the opposing team's kicker.

In certain leagues consisting of younger players, and in the short-lived professional Alliance of American Football, there are no kickoffs.