Hockey the game
The objective of the game is to score by playing a hard rubber disc, the puck, into one of the nets placed at opposite ends of the rink (the playfield). The players may control the puck using a long stick with a curved blade at one end. Players may also redirect or kick the puck with a skate (but not kick it into the goal) or with the hand (without closing the hand). A player scoring three goals in a single game is said to have scored a hat-trick. A "natural hat-trick" is when the player scores three goals consecutively. A team consists of at most 22 players of whom two have to be goaltenders. At most six players from each team may be on the ice at the same time. Usually one of the six is a goaltender (or goalie) who wears special protective clothing and is positioned in front of the net. The goaltender is allowed to immobilize the puck with his hands or body.
The other five players are divided into three forwards and two defencemen. The forward positions are named left wing, centre and right wing. Until recently forwards typically were played as units or lines, with the same three forwards always playing together. It is becoming common, however, for only the wingers to play together consistently. The defencemen usually stay together as a pair but may change less frequently than the forwards. Another innovation in lineups was the "torpedo" system which the Swedish briefly toyed with; it consisted of four defensive role players, and a torpedo who cruised near the off-sides line, even when the play was in the teams defensive end. The four defensive players would then essentially play the game as they would a power-play, hoping to capitalize on a quick liberating pass to their torpedo, to give him a one on zero opportunity. This innovation enjoyed limited success for them, and has largely been dropped, as their opponents found ways to de-claw the system.
Ice hockey is a fast paced game and player changes may happen every few minutes and often without an interruption in play.
The remaining characteristics of hockey often depend on the particular code of play being used. The two most important codes are those of the International Ice Hockey Federation (IIHF) and of the North American National Hockey League (NHL). North American hockey codes tend to bear much more resemblance to the NHL code.
The area of play is called a rink, which is 61 m (200 ft) in length and 26 to 30 m wide (85 to 100 ft) wide, with the corners rounded with a radius of 8 m (28 ft).
The rink is enclosed by boards that are between 1 m and 1.2 m (40 to 48 in) high. North American rinks are narrower than rinks elsewhere, typically about 85 feet wide compared to about 100 feet on other continents. Shatterproof glass extends above the boards, except in front of the players' benches. In the NHL, nets are suspended at each end of the rink to keep pucks from entering the crowd.
The surface of the ice is broken up into different sections by lines painted beneath the ice surface. The red goal lines are located at various distances from the end of the rink, depending on the code of play, and extend across the rink. International hockey dictates they be 3.5 m (10 ft) from each end of the rink, while NHL rules dictate they be 13 ft (3.96 m). The opening of the goals is located at the centre of the goal line, which means that there is an area behind the goal, which is rare for a team sport (box lacrosse, for one, also has an area behind the goal). In international play the goal 1.83 m wide and 1.22 m high, which is virtually identical to the North American specification of a goal 6 ft wide and 4 ft high. The goalposts are joined by a crossbar.
Attachments to the tops of the goal posts extend backwards towards the boards and permit the hanging of a net to catch pucks which cross the goal line between the goalposts.
The area just in front of the goal, which is restricted to the goaltender, is marked by another red line, and is called the goal crease. The dimensions of the crease in the National Hockey League and in international hockey differ. In international play the crease is a semi-circle with a radius of 1.8 m. In the NHL the crease is 8 ft (2.43 m) wide with sides 4.6 ft (1.4 m) long, and the front edge is a section of a semicircle 6 ft (1.82 m) in diameter. The surface of the concrete under the crease is painted light blue.
Two blue lines are drawn across the rink, dividing the rink into three parts. In the National Hockey League the blue lines are 60 feet from each goal line, while in international play they divide the rink into three equal parts.
The central part is known variously as centre ice or the neutral zone, while the other two zones are known either as the end zones or as the attacking and defending zones. The end zones are equal in size. One function of the blue line is to determine if the team with the puck is offside. A red and white checkered line (the red line) extends across the width of the rink and up the boards at centre ice, dividing the rink in half. This line is also used to determine if play is offside, as well as if the puck has been iced.
A player is offside if:
his (or her) team has the puck and he is already in the opponents' end zone when his team brings the puck into that end zone (across the blue line), in international play, if he is in the opponents' end zone and receives a pass which has crossed both blue lines, in most North American play, if he is on his opponents' side of the red line and receives a forward pass which has travelled across both his team's blue line and the red line. Icing consists of driving the puck from one's own side of the red line across the farther goal line without scoring and without the defending team having a chance to intercept it (in North America a defending player must also touch the puck behind the goal line before an attacking player does). Once icing occurs play is stopped and a face-off (see below) is held in the end zone of the team that iced the puck.
Play begins with a face-off at centre ice. The puck is thrown sharply to the ice between the centres of the opposing teams, who then attempt to play it. When play is stopped it is resumed with a face-off unless a penalty shot has been called. Face-offs are conducted in five face-off circles - one at centre ice and the other four on opposite sides of each end zone - at four dots, one at each end of each blue line in the neutral zone, or at other points as required by the rules.
The face-off circles have a radius of 15 ft in North America and 4.5 m in international play. There is a dot at the centre of each circle on which the puck is dropped. Only the centres may enter the face-off circles before the puck is dropped. Face-off tactics and strategy are extremely important parts of the game.