The game is played between two teams of eleven players (five reserve) each, on a 100 x 60 yard (91.4 m x 55 m) rectangular field. At each end there is a goal 7 feet (2.14 m) high and 12 feet (3.66 m) wide, and a semi-circle 16 yards (14.63 m) from the goal known as the shooting circle (or D or arc), with a dotted line 5 yards (5 m) from the semi-circle, as well as lines across the field 25 yards (22.9 m) from each end-line and in the center of the field. A spot, called the penalty spot or stroke mark, is placed 7 yards (6.4 m) from the center of each goal.
Rules of Hockey -
Each team has a maximum of 16 players, fielding 11 players, including a goalkeeper, at one time. The object of the game is to outscore your opponent over two 35-minute halves with 10 minutes break in the middle, making the actual time span 35-05-35. The only time attacking players can score a goal is when they are in the goal circle (also known as striking or shooting circle), a D-shaped area 14.6 meters from each goal.
Centre passes start each half and after each goal, with the team scored upon taking control. The player stands on the center spot and passes to a teammate at least one meter away. A coin toss determines who will take first possession, the other team starts the second half.
Low-scoring games are common in field hockey. As in soccer, teams tend to play a more defensive game with few goal-scoring chances. Players are more inclined to stay back and wait for the attacking players to advance. In an effort to add more scoring, the offside rule was suspended in 1998. No longer does attacking player have to keep the ball or defender ahead of them when moving into a scoring position.
The game begins with a toss of a coin and the winning captain can choose a starting end or start with the ball. The game time is divided into two equal halves of 35 minutes each, with five minutes for half-time. At the start of each half, as well as after goals are scored, play is started with a pass from the centre of the field. All players must start in their defensive half, but the ball may be played in any direction. Each team starts with the ball in one half, and the team that conceded the goal has possession for the restart.
Obstruction is called when players use their sticks or bodies to prevent another player from hitting the ball. The ball cannot be struck while in the air unless the player is shooting for the goal. Lifting the sticks above head level is considered a dangerous play and is not permitted.
The penalty for the above infractions is loss of possession of the ball, unless one of the two referees deems it to be a serious offense, in which case they can then issue one of three coloured cards. A green card issues a warning, a yellow card suspends the offending player for at least five minutes, and a red card ejects the offending player.
Tackling is permitted as long as the tackler does not make contact with the attacker or his stick before playing the ball (contact after the tackle may also be penalised if the tackle was made from a position where contact was inevitable). Further, the player with the ball may not deliberately use his body to push a defender out of the way.
When the ball passes over the sidelines, it is returned to play with a sideline hit, taken by a member of the team whose players were not the last to touch the ball before crossing the sideline. If it crosses the backline after last touched by an attacker, a 15 m hit. A 15 m hit is also awarded for offenses committed by the attacking side within 15 m of the end of the pitch they are attacking.