The Offside Rule Explained (With Examples)

The rule in one paragraph

A player is in an offside position when any part of the head, body or feet with which they can legally play the ball is nearer to the opponents' goal line than both the ball and the second-last opponent (usually the last outfield defender) at the moment the ball is played by a teammate. Being in an offside position is not itself an offence — it becomes one only when the player then becomes involved in active play.

The two-step test

Every offside decision applies two questions in order. First: was the attacker in an offside position when the ball was played? Second: did that attacker then interfere with play, interfere with an opponent, or gain an advantage from being in that position? If either answer is 'no', there is no offside.

An attacker who is in an offside position but stands passively while a teammate scores from onside is not offside. An attacker in an offside position who blocks the goalkeeper's view — even without touching the ball — is offside.

Who counts as the second-last opponent

In practice the second-last opponent is almost always the last outfield defender, because the goalkeeper is the last opponent. But when the goalkeeper is out of position — say, up for a corner — the rule still uses the second-last opponent, which can be a defender behind the goalkeeper. This is why 'offside is measured against the last defender' is a shortcut, not the rule.

Where offside cannot occur

A player cannot be offside directly from a goal kick, a throw-in or a corner. This is why teams often use throw-in routines to release runners behind the defensive line. A player is also not offside in their own half at the moment the ball is played.

Active play: interfering, obstructing, gaining advantage

Since the 2016 rewrite of Law 11, 'gaining an advantage' includes playing a ball that rebounds off the post, crossbar, an opponent or a match official — and also playing a ball from a deliberate save by an opponent. A deliberate play by a defender, though (a controlled clearance, for example), resets the offside phase.

How VAR checks offside

For goals, the VAR draws two lines: one on the attacker's rearmost legal body part, one on the second-last defender's rearmost legal body part, at the frame the ball was struck. If the attacker's line is ahead, it is offside. This is why toenail offsides became a talking point.

Semi-automated offside technology (SAOT), used at the 2022 and 2026 World Cups and in the Champions League, tracks 29 body points per player at 50 frames per second and produces a decision within seconds — reducing both errors and delays.

Why offside was invented

The earliest football codes of the 1860s allowed no forward passes at all. The offside rule was introduced to prevent 'goal-hanging' — attackers loitering near the opponents' goal waiting for long balls. The three-defender rule (an attacker was onside if three defenders were between them and the goal line) applied from 1866 to 1925, when it was reduced to two defenders — a change that immediately doubled the number of goals scored.

Common misconceptions

Level is onside — offside requires the attacker to be nearer the goal line than the defender, not level with them. Being in front of the ball when a teammate passes it forward is not automatically offside — only the position at the moment the ball is played matters. And a player who is offside can become onside if a defender then deliberately plays the ball to them.

The debate over the future of the rule

Arsène Wenger's proposal — that a player should be onside as long as any part of their body is level with the defender — has been trialled and is under consideration by IFAB. Supporters argue it would encourage attacking play; opponents warn it would tilt the game further toward attackers in an era already producing record goalscoring totals.