The short answer: A player commits an offside offence only if they were in an offside position when a team-mate played or touched the ball and then became involved in active play. Being in an offside position on its own is not an offence.
When is a player in an offside position?
Under IFAB Law 11, the relevant parts of a player’s head, body or feet must be in the opponents’ half and nearer to the opponents’ goal line than both the ball and the second-last opponent. Being level is not offside. The hands and arms do not count when determining position.
The reference is usually the second-last opponent, not necessarily the last outfield defender. A goalkeeper may be ahead of another defender, and the offside line follows the actual positions of the players.
When does the position become an offence?
The key question is whether the player becomes involved in active play at the relevant moment. They may do this by playing or touching a ball passed or touched by a team-mate, interfering with an opponent, or gaining an advantage in circumstances defined by Law 11.
Interference with an opponent can include clearly obstructing their line of vision or challenging for the ball. Simply appearing in the camera frame near the goalkeeper is not automatically enough.
An offside offence is punished with an indirect free kick to the defending team, subject to the specific procedures in Law 11.
Why the moment the ball is played matters
Offside is assessed when a team-mate plays or touches the ball, rather than when the receiver eventually collects it. A player can run behind defenders after the pass and still be onside if they were correctly positioned at the relevant moment.
A deflection from an opponent does not necessarily reset the offside situation. Deliberate play by an opponent and a deliberate save are treated differently under the law, and identifying which occurred can require careful judgment.
How VAR and offside technology work together
For a possible offside preceding a goal or another reviewable event, VAR can study available angles and positioning data. Semi-automated offside technology can help identify the moment of the touch and the relevant player positions, but video officials still validate the information and its application.
Technology can improve the measurement of where players were. It does not remove all subjective questions, especially whether a player interfered with an opponent or whether a defender deliberately played the ball.
Common offside questions
Does an arm count for offside?
No. Hands and arms are excluded for all players, including goalkeepers; the boundary is aligned with the bottom of the armpit.
Is standing offside a foul?
No. A position becomes an offence only with the relevant involvement in active play.
Can VAR disallow a goal for offside?
Yes. Offside in the attacking phase of a goal is within the current VAR review protocol.
What do you think about VAR?
VarVote has one ongoing, voluntary yes-or-no question on whether football should keep video refereeing. It is not a scientific survey.
Explore the permanent VAR vote →Primary sources and further reading
Reference material from the body responsible for the Laws of the Game. Always check the current version when interpreting a later season.