No rule in football causes more confusion, or more arguments, than offside. Yet at its core it is straightforward, and understanding it properly will change how you watch every match of the World Cup. Let us clear it up once and for all.
The basic rule
A player is in an offside position if, at the moment a teammate plays the ball, he is in the opponent’s half and nearer to the opponent’s goal line than both the ball and the second-to-last defender (usually the last outfield defender, with the goalkeeper being the last). Being in that position is not itself an offence — the player is only penalised if he then becomes involved in the play: receiving the ball, interfering with an opponent, or gaining an advantage from that position.
Two details trip people up. First, the position is judged at the instant the ball is played by the teammate, not when it is received — a player can be onside when the pass is made and yards beyond the defence when he collects it, and still be legal. Second, you cannot be offside from your own half, nor directly from a corner, throw-in or goal kick.
What it is not
Offside is not about where the player is when he touches the ball; it is about where he was when the ball was played to him. It is not an offence to stand in an offside position all day if you never get involved. And a player level with the last defender is onside — the benefit of the doubt, in the letter of the law, goes to the attacker.
Most crowd fury at offside decisions comes from watching the wrong moment: fans see a player clean through and cry foul, forgetting that the relevant instant was the pass, seconds earlier, when he may well have been level.
How VAR changed the feel
Video review made offside forensic. Officials can now freeze the exact frame the ball is played and draw lines to the millimetre, catching offsides invisible to the naked eye — and disallowing goals for a shoulder or a toe. That precision is fairer in theory and colder in practice: the marginal, drawn-line offside has become one of the tournament’s most divisive sights, and the debate over how tight is too tight will follow the game into 2026 and beyond. But the underlying law has not changed. Watch the moment of the pass, and you will rarely be fooled again.