The Offside Rule turns 100: Hear The Guardian’s Jonathan Wilson tell the story

The year 2025 marks the 100th anniversary of the change to the offside rule, which meant that only two defending players were required to play an attacker onside instead of three.

Jonathan Wilson, who is visiting Malmö City Archives on September 23, is one of the world’s leading football historians and he will be talking about the history of the offside rule during the evening. Wilson is the author of around ten books and writes regularly about football for the English daily newspaper The Guardian.

The offside rule of 1925, Law 11 in the Laws of the Game established by the International Football Association Board (IFAB), is a fundamental component of association football designed to prevent goal-hanging and ensure a fair contest between attackers and defenders.

A player is in an offside position if they are nearer to the opponents’ goal line than both the ball and the second-last opponent (which is typically the last outfield player, as the goalkeeper is usually the last) at the moment the ball is played to them. It is crucial to note that being in an offside position is not an offence in itself.

A player in an offside position is only penalized if, at the precise moment the ball is touched or played by a teammate, they are deemed to be “involved in active play.” This can be judged in three ways:

1. 1. Interfering with play: Playing or touching the ball passed by a teammate.
   2. Interfering with an opponent: Preventing an opponent from playing or being able to play the ball by clearly obstructing their line of vision or movements.
   3. Gaining an advantage: Playing the ball after it has rebounded off a goalpost, crossbar, or an opponent.

There are, however, exceptions. A player cannot be offside if they receive the ball directly from a goal kick, a corner kick, or a throw-in. Furthermore, a player is not offside if they are in their own half of the field or level with the second-last opponent or the last two opponents at the moment the ball is played.

The enforcement of the rule is the responsibility of the assistant referees (linesmen), who signal an offside offence by raising their flag. However, with the introduction of the Video Assistant Referee (VAR) technology in high-level competitions, decisions can be reviewed and corrected for clear errors.

The offside offence is punished by an indirect free kick for the opposing team from the place where the offside player was involved in active play. The rule’s interpretation, particularly regarding “active play,” has evolved to promote attacking football and reduce stoppages, but it remains one of the most complex and debated aspects of the sport.