Offside (ice hockey)

In ice hockey, a play is offside if a player on the attacking team does not control the puck and is in the attacking or offensive zone when a different attacking player causes the puck to enter the offensive zone, until either the puck or all attacking players leave the offensive zone. Simply put, for a play to not be offside, the puck must enter the attacking zone before attacking players, and the offensive team cannot play the puck when offside.

For determining offside, the position of the puck and players must be considered to be in the neutral or offensive zone. Usually, the puck enters or leaves the offensive zone when it completely crosses the blue line. A player is in the neutral zone if either skate is in the neutral zone or touches the imaginary plane extending upwards from the leading edge of the blue line; otherwise, they are in the offensive zone.

Being offside is generally not permitted; under some rule sets, an offside violation occurs as soon as a play goes offside (known as an immediate offside), while under others, it occurs only when attacking players play the puck after going offside and then failing to completely exit the offensive zone (known as a delayed offside). When an offside violation occurs, a linesman will stop play. To restart play, a faceoff is then held at the ice spot closest to the infraction, usually a neutral spot, or if there is a delayed penalty, at a spot in the defending zone of the defending team, which incurred the penalty. Even if the linesman erred in calling offside, the faceoff will still occur.