A player is in an offside position when part of the head, body or feet is in the opposition half and nearer the goal line than both the ball and the second-last opponent. The hands and arms do not count.
Position alone is not an offence. The attacker must become involved by playing the ball, challenging an opponent or gaining an advantage from a rebound or save. The crucial reference point is the instant a teammate touches or plays the ball, not when the pass arrives.
If offside is confirmed, the defending team receives an indirect free-kick from the location of the offence.
The rule does not apply when a player receives the ball directly from:
These restarts can place an attacker beyond the defensive line without producing an offside offence. A player level with the second-last opponent is also onside, as is an attacker behind the ball when the teammate plays it.
Semi-automated offside technology is intended to identify the kick point and the relevant body positions more quickly. The report says the system was used at the 2022 World Cup in Qatar, supporting video officials and the referee rather than replacing the final decision.
That distinction matters. Technology can draw lines, but officials must still judge whether an attacker interfered with an opponent or gained an advantage. The most contentious incidents may therefore shift from pure positioning to interpretations of active involvement.
The rule will remain a tactical battleground in 2026. Attackers will continue testing defensive lines with timed runs, while coaches ask defenders to step up together. The next major storyline will be whether faster technology reduces delays-or simply makes marginal decisions more visible.