National Hockey League rules

While the National Hockey League (NHL) follows the general rules of Ice hockey, it differs slightly from those used in international games organized by the International Ice Hockey Federation such as the Olympics.

Game timing
In the National Hockey League, between stoppages of play, teams have 18 seconds (5 seconds for the visiting team, 8 seconds for the home team, 5 seconds to line up at the faceoff location) to substitute their players, except during TV timeouts. TV timeouts are two minutes long, and occur three times per period: during normal game stoppages after the 6, 10, and 14 minute marks of the period, unless there is a power play or a goal has just been scored. Each team may also take one 30 second time-out which may only be taken during a normal stoppage of play.

Hockey rink


The hockey rink is an ice rink which is rectangular with rounded corners and surrounded by a wall, usually called the "boards". It measures 25.91 by 60.92 metres (85 by 200 feet) in the NHL, while international standards call for a rink measuring 60-61 meters long by 29-30 meters wide (196.85-200.13 feet by 95.14-98.43 feet). The centre line divides the ice in half lengthwise. The centre line is used to judge icing violations. There are two blue lines that divide the rink roughly into thirds. They divide the ice into zones. Near each end of the rink, there is a thin red goal line spanning the width of the ice. It is used to judge goals and icing calls.

New in the 2005-06 season, after testing in the American Hockey League, is a trapezoid behind each goalie net. The goalie can only play the puck within that area or in front of the goal line. If he plays the puck behind the goal line and not in the trapezoid, a 2 minute minor penalty for delay of game will be assessed by the referees. This rule is widely referred to as the "Brodeur rule", after New Jersey Devils goalie Martin Brodeur, whose puckhandling behind the net is believed to be the cause for the rule.

Scoring and winning
A goal is scored when the puck completely crosses the goal line and enters the net. A goal may be disallowed under the following circumstances:
 * the scoring team takes a penalty during the play;
 * the puck is directed in by an attacker's high stick (above the crossbar), glove, or skate (with a distinct kicking motion--angling one's skate is allowed);
 * goaltender interference
 * the puck goes in after the Referee intends to stop play;
 * the puck goes in after the green light (behind the goals) comes on, signaling the end of the period. (Hockey does not allow for "buzzer shots.")

The team with more goals at the end of regulation time wins the game. If a regular-season game is tied at the end of regulation, the game enters a five-minute, 4-on-4 sudden-death overtime period; any team that scores during overtime immediately ends the game with a victory. If neither team scores during this time, a shootout takes place. Three players from each team are picked by their respective coaches and alternate chances to score on the opposing goaltender, in a method functionally identical to penalty shots. This sequence ends when one team mathematically has to have more shootout goals than the other, thus winning the game. If neither team emerges victorious, the shootout continues one frame at a time until one team scores and the other does not, in which case the team who scores, wins. No player may shoot twice until everyone on the bench has taken a shot.

A team that loses a game in overtime or the shootout will receive one point in the standings; the awarding of game points to losing teams is a point of debate among fans and the media.

Shootouts are not implemented in the playoffs. If a playoff game is tied at the end of the regulation, the game instead enters a twenty-minute 5-on-5 sudden-death overtime. The game continues indefinitely in this format until a goal is scored; the team that scores this goal immediately wins the game. Additional 20-minute overtime periods are played as necessary until the winning goal is scored.

Offside
In ice hockey, play is said to be offside if a player on the attacking team enters the attacking zone before the puck (unless the defensive team brings the puck into their own zone). When an offside violation occurs, the linesman blows the play dead, and a faceoff is conducted in the neutral zone. During the '04-'05 lockout, the league removed the offside pass or two-line pass rule, which required a stoppage in play if a pass originating from inside a team's defending zone was completed on the offensive side of the centre line, unless the puck crossed the line before the player. The removal of the two-line offside was one of several rule changes intended to increase overall scoring, which had been in decline since the early 1990's.

Icing
Icing occurs when a player shoots the puck across both the centre line and the opposing team's goal line without the puck going into the net. When icing occurs, a linesman stops play if a defending player (other than the goaltender) touches the puck before an attacking player is able to. Play is resumed with a faceoff in the defending zone of the team that committed the infraction. Icing is not enforced for a team that is short-handed. If the goaltender makes a move from his net to play the puck, the icing is immediately waved off (In contrast to Minor and International Hockey, where the goaltender must play the puck for it to be waved off). Icing can also be waved off if, in the officials' opinion, the defending team had a viable opportunity to play the puck before crossing the goal line.

Under the rules following the 2004-2005 lockout if a team is guilty of icing the puck they are not allowed to make a line change before the following faceoff.

Penalties
A penalty is a punishment for infractions of the rules. A referee makes all penalty calls while the linesmen may call only obvious technical infractions such as too many men on the ice. In the NHL, the linesman may also call major intent-to-injure penalties that the referee may have missed.

During a penalty, the player who committed the infraction is sent to the penalty box. Small infractions are deemed minor penalties, and the player is kept off the ice for two minutes of gameplay. More dangerous infractions, such as fighting, are deemed major penalties and have a duration of five minutes. The penalized team cannot replace the player on the ice and is thus shorthanded for the duration of the penalty. Normally, hockey teams have five skaters on the ice (excluding the goaltender), so if a minor or major penalty is called, play becomes five-on-four.

This situation is called a power play for the non-offending team and a penalty kill for the offending team. A team is far more likely to score on a power play than during normal play. If the penalized team is scored on during a minor penalty, the penalty immediately terminates. Unlike minor penalties, major penalties must be served to their full completion, regardless of number of goals scored during the power play.

There are exceptions to the rule where a team cannot replace a player on the ice after a penalty: mutual majors for fighting, where there are two participants in a fight, will result in each person receiving five minutes, but the penalties will not affect the on-ice strength of either team (play remains five-on-five), unless if a player is deemed to be the instigator of the fight, that player will receive a two minute minor. There are also "coincidental" minors in which the penalties called against both teams are simultaneous and equal in length, so that neither team receives a power play. The players are let out of the penalty box at the stoppage of play

There also exist game- and 10-minute-misconducts which are reserved for infractions such as continued disputing of a call with an official or for intent to injure penalties. Misconducts do not affect the on-ice strength of the offending team, though they are usually accompanied with a minor, double minor, or five-minute major.

Various combinations of penalties may also result in match-ups such as 5-on-4, 5-on-3, 4-on-3, 4-on-4 or (rarely) 3-on-3.