In ice hockey, a player is offside if both skates are completely over the opponent’s blue line before the puck fully crosses that line. In other words, the puck must lead the attackers into the offensive zone. The position of the skates decides offside, not the stick or body. A player is onside if at least one skate is on the blue line, or in the NHL above it without having fully crossed, when the puck enters the zone. When a player enters early, the linesman either stops play right away or signals a delayed offside, which can be cleared if all attackers leave the zone. After an offside stoppage, the faceoff usually takes place in the neutral zone.
Offside at a glance
| Concept | Explanation |
|---|---|
| Deciding factor | Position of the skates, not the stick or body |
| Onside | At least one skate on or, in the NHL, above the blue line when the puck crosses |
| Offside | Both skates fully across the blue line before the puck |
| Delayed offside | Linesman raises an arm; play continues while the defending team can play the puck |
| Tag-up | All attackers leave the zone to clear a delayed offside |
| Faceoff | Usually in the neutral zone after an offside call |
How the offside line works
The blue line belongs to the zone the puck is in. For the puck to be in the offensive zone, it must completely cross the outer edge of the blue line. For a player to be offside, both skates must be completely past the same line before the puck. Linesmen watch the blue line closely as attackers enter the zone, often positioning themselves along the line to judge whether players entered early. Because the rule depends on the skates and the whole puck, close plays can be very tight.
Delayed offside explained
If an attacker enters the zone early but the defending team gains or can play the puck, the linesman may signal a delayed offside by raising an arm instead of stopping play immediately. The attacking team must then clear the zone, meaning every attacker must return to the neutral zone or touch the blue line, often called tagging up. Once all attackers have cleared, the linesman lowers the arm and the attackers can re-enter. If an attacker touches the puck or pressures the puck carrier in the zone before tagging up, play stops for offside. In some situations, a deliberate offside can move the faceoff to the offending team’s end of the ice.
The puck carrier exception
Under NHL rules, a player who is controlling the puck and carries it into the zone is not offside even if their skates cross the blue line before the puck, for example when skating backward while stickhandling. This exception allows skilled players to make controlled entries without being penalized for body position relative to the puck. Other attackers, however, must still follow the normal offside rule.
Offside examples
Example 1: A winger skates ahead of the puck carrier and crosses the blue line with both skates before the puck enters. The linesman stops play for offside, and the faceoff moves outside the zone. Example 2: A forward reaches the blue line early but keeps one skate on the line, gliding along it until the puck crosses. This player is onside and can join the attack. Example 3: An attacker is already in the zone when a teammate dumps the puck in, but a defender picks it up first. The linesman signals delayed offside, and the attacker skates back to touch the blue line. Once every attacker has tagged up, the arm goes down and play continues normally. Example 4: A skilled forward carries the puck into the zone while skating backward, so their skates cross first. Under NHL rules, this is not offside because the player controls the puck.
Zone entry strategy
Offside shapes how teams attack. Controlled entries, where a player carries the puck across the blue line, allow teams to maintain possession but require good timing among teammates. Dump-ins, where the puck is shot into the zone for forwards to chase, reduce offside risk but give up possession. Coaches often design entry plays with specific timing, such as one forward driving wide with the puck while others time their routes to stay onside. Strong communication and awareness of the blue line help teams avoid offside calls that stall attacks.
The role of linesmen
Linesmen are responsible for calling offside and icing, conducting most faceoffs and breaking up altercations. They position themselves along the blue lines as play moves up the ice, giving them the best angle to judge whether attackers entered early. Their calls require quick reactions, since players and the puck can cross the line within fractions of a second. Clear signals, such as extending an arm for a delayed offside, help players understand what is happening.
How to avoid going offside step by step
- Watch the puck carrier as you approach the blue line.
- Time your entry so you cross the line just after the puck.
- Keep a skate on the line if you arrive early.
- Use crossovers or glides along the line to hold position.
- Communicate with calls like onside, wait or tag up.
- Tag up quickly when a delayed offside is signaled.
- Avoid touching the puck in the zone until you are onside.
Offside and goals
A goal can be disallowed if the play that led to it began with an offside entry. In the NHL, coaches can challenge a goal on the basis of offside, and officials review video to determine whether the attacking team entered the zone legally. Recent NHL rules have narrowed the time window for such challenges and added penalties for unsuccessful ones, such as a minor penalty for delay of game. Rule changes around challenges and skate position have made offside reviews a regular part of modern professional hockey.
Offside in different leagues
Offside rules are similar across most leagues, but details vary. The NHL and many other leagues removed the two-line pass rule years ago, so passes across the center red line are allowed. The NHL also changed its rule in 2021 so that a skate above the blue line, even if not touching the ice, counts as onside as long as it has not fully crossed. Some amateur leagues handle delayed offside and tag-up differently. Rules note: this summary is based mainly on NHL rules and simplified; offside rules vary between the NHL, IIHF and amateur bodies such as USA Hockey and Hockey Canada, so check the current rulebook for your league.
Why offside exists
The offside rule prevents attackers from waiting deep in the offensive zone for long passes, sometimes called cherry-picking. It forces teams to move the puck into the zone together, creating more structured, competitive play at the blue line. Without it, the game would become more about long stretch passes than skating, passing and zone entries.
Common mistakes to avoid
- Crossing the line ahead of the puck without watching the carrier.
- Forgetting to tag up during a delayed offside.
- Pressuring the defender before clearing the zone on a delayed offside.
- Poor communication between linemates on entries.
- Assuming the stick position matters. Only the skates decide.
- Rushing entries instead of waiting for the puck to lead.
Frequently asked questions
What decides offside in hockey?
The position of the skates relative to the blue line when the puck completely crosses it.
What is a delayed offside?
When an attacker is offside but the defending team can play the puck, play continues until attackers tag up or touch the puck.
Where is the faceoff after offside?
Usually in the neutral zone, near the blue line where the offside occurred.
