onside

Onside, also written onside, is a term used in sports to indicate that a player or team is in a permissible position under the rules, in contrast with offside. The term originates from the idea of being on the correct side of a line or position during play and is used more as a functional descriptor than as a single rule.

In association football (soccer), a player is onside if they are not in an offside position when the ball is played to them. An offside position typically exists when a player is nearer to the opponent’s goal line than both the ball and the second-last opponent (usually the last defender excluding the goalkeeper) at the moment the ball is played to them. A player who is onside may receive a pass and participate in play without an infringement; a player who is offside is penalized by a stoppage and an indirect free kick for the opposing team.

In American football, onside is most commonly encountered in relation to onside kicks. An onside kick is a kickoff intended to be recoverable by the kicking team, usually used late in a game to regain possession. The ball must travel at least 10 yards before the kicking team can touch it, unless the receiving team touches it earlier, and the kicking team must recover the ball to maintain possession.

Other uses of the term appear in general English to describe alignment with rules or norms, and in various proper names and brands that use OnSide or onside in their titles. The core sense remains the alignment with the rules and the legal participation in the ongoing play.