What Is Offside in Hockey?

Offside is called when a member of the attacking team crosses the offensive blue line into the attacking zone before the puck crosses it. In simple terms, the puck must enter the zone first, or at the same time as the player. If an attacker gets in ahead of the puck, the play is offside, whistled dead, and restarted with a faceoff outside the zone.

It comes down to skate position relative to the blue line. A player is onside as long as at least one skate is touching or behind the blue line when the puck crosses it. If both skates are fully over the line into the zone before the puck, it is offside. The blue line itself counts as part of the zone boundary, so being on the line keeps a player onside.

A delayed offside happens when attackers enter the zone ahead of the puck but do not touch it. The linesman raises an arm instead of blowing the whistle, giving the attacking team a chance to clear the zone — have all players exit back over the blue line — which 'washes out' the offside and lets play continue. If they touch the puck first, the whistle goes and a faceoff follows.

Play stops and a [faceoff](/what-is-a-faceoff-in-hockey/) is held at one of the neutral-zone faceoff dots just outside the blue line where the offside occurred. No penalty is assessed — offside is a stoppage, not an infraction that sends anyone to the box. It simply resets the play so the attacking team must re-enter the zone legally, with the puck leading the way.

Both are stoppages that reset play with a faceoff, but they involve different lines and situations. Offside is about attackers entering the offensive zone ahead of the puck at the blue line. [Icing](/icing-in-hockey-rules-explained/) is about shooting the puck from your own half all the way across the opponent's goal line untouched. Offside governs entering the zone; icing governs dumping the puck the length of the ice.

Yes. In the NHL, a team can challenge a goal on the grounds that the scoring play began with an offside zone entry. Officials review video to check whether an attacker preceded the puck over the blue line on the entry that led to the goal. A successful challenge wipes out the goal; an unsuccessful one can result in a minor penalty, so coaches use it carefully.

It exists to keep the game flowing and fair by preventing 'cherry-picking' — an attacker loitering in the offensive zone waiting for a long pass. By requiring the puck to enter the zone first, offside forces teams to carry or pass the puck into the attacking zone as a unit, which is central to how hockey's zones and strategy work.