Offside rule (association football)

How the rule works in practice

Referees and assistant referees must judge several factors simultaneously: the exact moment the ball is played by a team-mate, the relative positions of players, and whether the player in an offside position becomes involved in play. The offence is judged at the instant the ball is played, not when it is received. If an offside offence occurs, play is restarted with an indirect free kick to the defending team from the place where the offence took place.

What counts as involvement in active play

• Playing or touching the ball after it is played by a team-mate.
• Interfering with an opponent, for example by obstructing a goalkeeper’s line of sight, blocking movement, or making a challenge for the ball.
• Gaining an advantage from being in that position, such as receiving the ball from a rebound off the goalpost, crossbar or an opponent.

A player who is in an offside position but not involved in active play is considered to be passive and should not be penalised.

Common exceptions and special cases

There are clear situations in which a player cannot be penalised for offside. A player is not offside if they are in their own half at the moment the ball is played. Additionally, no offside offence is called when a player receives the ball directly from certain restarts: goal kicks, throw-ins and corner kicks. Other nuanced scenarios arise when the ball is deliberately played by an opponent or when the ball takes an unexpected deflection—these can alter whether an offside offence is judged to have occurred.

History, interpretation and modern developments

The offside concept has existed since the early codification of association football and has evolved through successive clarifications by the sport's law-making body, the IFAB. Interpretations have shifted from a strict positional restriction to a focus on involvement in play and fair competition. In recent years, video review systems have been introduced to help officials make marginal calls. Video assistant referees (VAR) and emerging semi-automated tracking technologies aim to identify the exact moment of the pass and the relative positions of players, reducing human error but sometimes increasing debate over very small margins.

Practical examples and controversies

In everyday play, offside decisions shape tactics: defenders use a high line to catch attackers offside, while attackers time runs to stay level with the second-last defender. Controversy often arises from fast, split-second passes and tight margins where the attacker’s shoulder or toe may be fractionally ahead of a defender. Critics point to subjective judgements such as what constitutes "interfering with an opponent," while proponents of technology argue for clearer, reproducible decisions. Match officials, including the assistant referee, remain responsible for applying the rule on the field, with video review intended to assist but not to replace on-field judgment.