A player is in an offside position if they are nearer to the opponents' goal line than both the ball and the second-to-last opponent when the ball is played.

This forms the foundational component of the offside rule. For a player to be deemed in an 'offside position,' two primary criteria must be met simultaneously: firstly, the player must be in the opposing team's half of the field. Secondly, and critically, at the exact moment the ball is played by a teammate, the player must be positioned closer to the opponent's goal line than the ball itself and closer than the second-to-last opponent (which is usually the last outfield player, as the goalkeeper is typically the very last opponent). It's vital to stress that merely being in an offside position is not an offense in itself. It is a precursor to a potential offense, requiring further action or involvement in play. The timing is paramount; the position is judged at the moment the ball is passed or touched by a teammate, not when the player receives the ball.