A kickoff is a method of starting a drive in American football and Canadian football. Typically, a kickoff consists of one team – the "kicking team" – kicking the ball to the opposing team – the "receiving team". The receiving team is then entitled to return the ball, i.e., attempt to advance it towards the kicking team's end zone, until the player with the ball is tackled by the kicking team, goes out of bounds, or scores a touchdown. Kickoffs take place at the start of each half of play, the beginning of overtime in some overtime formats, and after some scoring plays.
Common variants on the typical kickoff format include the onside kick, in which the kicking team attempts to regain possession of the ball; a touchback, which may occur if the ball is kicked into the receiving team's end zone; or a fair catch, in which a player on the receiving team asks to catch the ball without interference from the kicking team, waiving his entitlement to attempt a return rush. 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 or placed at receiving team's 40-yard line, whichever is farther).
A kickoff occurs at the start of each half and before each overtime (in the National and Arena Football Leagues). It is also traditionally decided by a coin toss at the beginning of each game carried out by the referee. The visiting team captain calls either heads or tails. The winner of the coin toss elects whether to take first choice in the first half or the second half. The captain with first choice then picks either a team to kick off or an end of the field to defend. The other captain chooses the remaining option. At the beginning of the second half, the two captains choose in the reverse order. If an overtime is required, another coin toss takes place to decide who gets first possession during the overtime. After a touchdown the scoring team kicks the ball off to the opposing team. In American football a field goal also results in a kickoff by the scoring team, but in Canadian football the scored-against team has an option of scrimmaging from their 35-yard line or receiving a kickoff.