The offside rule in soccer is widely regarded as the sport’s most contentious and intricate regulation, a status that dates back 163 years to its original codification.
At its core, the rule demands that an attacking player must not be positioned beyond the second‑to‑last defender when the ball is passed to them in the opponent’s half.
Match officials traditionally rely on a network of assistant referees’ flags and Video Assistant Referee (VAR) systems to judge whether a player is offside, especially in high‑stakes moments.
FIFA has long encouraged referees to let play continue until a natural stoppage, thereby avoiding premature calls that could disrupt the flow of the game.
The Dawn of Semi‑Automated Offside Technology
Semi‑automated offside technology (SAOT) now equips officials with the ability to measure offside positions down to the millimetre, delivering precise data that can be trusted for critical decisions.
During the 2026 World Cup, SAOT will transmit audio alerts to referees the moment a player is found to be offside by at least ten centimeters, streamlining the review process.
The new system is designed not only to improve accuracy but also to reduce the risk of injuries that can arise from prolonged stoppages, while preserving the integrity of match outcomes.
However, the technology has its limits; it struggles to make determinations when multiple players cluster together, requiring human judgment in those complex scenarios.