offside

In sports like football (soccer) and ice hockey, the offside rule prevents players from gaining an unfair advantage by positioning themselves too close to the opponent's goal.

In football, a player is offside if, at the moment the ball is passed, they are closer to the opponent's goal line than both the ball and the second-to-last defender, and they are actively involved in play. Simply being in an offside position is not an offense; a penalty occurs only if the player receives the ball or interferes with play. The rule does not apply in a player's own half or from certain restarts like throw-ins or goal kicks.1

In ice hockey, play is ruled offside if a player makes or takes a pass that travels across two blue lines, or if they precede the puck into the attacking zone. This results in a face-off.2