How hockey works.

The basic idea

A team scores by sending the puck into the opponents' goal, and the team with more goals wins. Each side has a goaltender, who guards the net, and five skaters in front of them: usually a centre, two wingers and two defenders (see positions). Hockey Canada's 2026-28 Playing Rules (Rule 2.1) say a team may have no more than six players on the ice while play is in progress. The IIHF Official Rule Book 2026/27 (Rule 5.3) allows only one goaltender on the ice per team, and lets a team pull its goaltender for an extra skater, who does not get the goaltender's privileges.

How many players a team dresses

The NHL's game line-up is separate from its season roster. The NHL's Hockey Operations Guidelines say a club must carry at least 20 players (18 skaters and 2 goaltenders) and no more than 23 on its playing roster from the start of the regular season to the trade deadline. Under Hockey Canada's 2026-28 rules, a player registered as a goaltender may play only as a goaltender. The USA Hockey 2025-29 rulebook text was not available for this site, so its roster limits are not given here.

Line changes

Skaters work in short shifts and swap with teammates on the bench, often without any stoppage. The IIHF's 2026/27 Rule 74.1 allows a change on the fly as long as the player leaving is within 1.50 m of the bench and out of the play before the replacement joins it. At stoppages the NHL uses a set order under its 2026-2027 Rule 82.2: the visiting team gets up to five seconds to change, then the home team gets up to eight. A team that ices the puck may not change players before the next faceoff under the IIHF and NHL rules, apart from a few exceptions such as replacing an injured player or returning a pulled goaltender; Hockey Canada's 2026-28 rules apply the same "no change on icing" rule in U18 AAA, Junior and, if a Member chooses, Senior (see offside and icing).

Periods, intermissions and time-outs

"Actual play" means the clock stops whenever play stops, so a game lasts much longer than 60 minutes of wall-clock time. Hockey Canada's rule says the full-length format must be used in games between Members and in national competition; local games can be shorter.

When the score is tied

This is where the rulebooks differ most.

Penalties change the numbers in overtime. Under the IIHF's Rule 84.3 a penalised team plays short, so strength becomes 4 on 3, and a two-man advantage becomes 5 on 3. The NHL's Rule 84.3 also gives 4 on 3 for a single penalty and 5 on 3 when a two-man advantage applies, and neither rulebook lets a team drop below three skaters. A team may pull its goaltender for an extra skater in overtime under both. In the NHL, a team that loses while its goaltender is pulled forfeits the point it earned for the tie, unless the goaltender left for a delayed penalty (Rule 84.2).

Shootouts

A shootout is a series of one-on-one attempts against the goaltender, taken under each rulebook's penalty-shot rules.

• IIHF 2026/27 (Rule 84.4): the referee tosses a coin with the captains and the winner chooses to shoot first or second. Five different shooters per team alternate, and they do not need to be named in advance. If it is still tied, the tie-break continues one pair at a time, and the same player may shoot each time. Only the deciding goal is added to the score.
• NHL 2026-2027 (Rule 84.4): the home team chooses whether to shoot first or second. Each team gets three shots unless it is decided sooner, then it goes to sudden death, and no player may shoot twice until every eligible player has shot. The final score gives the winner one more goal than the loser had after overtime, and the player who scores the game-winning shootout goal is not credited with a goal in personal statistics.

Standings points

The IIHF's Rule 78.1 gives 3 points for a regulation win. In a round robin or preliminary round, a game decided in overtime or a shootout gives the winner 2 points and the loser 1. The NHL's Rule 78.1 gives 2 points for a win; if a regular-season game is tied after three periods, each team gets one point (Rule 84.1), and the team that wins in overtime or the shootout ends with two (Rule 78.1). Hockey Canada's Rule 6.17 credits a win to the team with more goals after regulation, and its Rule 6.16 leaves overtime formats to its Members and leagues.

How the NHL got here

According to Sports Illustrated (2025), NHL regular-season overtime returned in 1983 as a five-minute period, and ties remained possible until the shootout era began after 2005. Sports Illustrated also gives 1921 and 1927 dates for earlier overtime formats; they come from that one source and could not be confirmed. The Globe and Mail reported that on 24 June 2015 the NHL Board of Governors switched regular-season overtime from 4 on 4 to 3 on 3, starting in 2015-16, to reduce the number of games settled by shootouts. The same meeting approved the coach's challenge, explained on the officials page.

For 2026-27, Bleacher Report (27 September 2026) says each NHL team plays 84 regular-season games, up from 82, with preseason capped at four games. NHL.com says the season opened on 29 September 2026, and as of October 2026 it is in progress.