Men's lacrosse is a contact game played by ten players: a goalie, three defensemen, three midfielders and three attackmen.
Each team must keep at least four players, including the goalie, in its defensive half of the field and three in its offensive half. Three players (midfielders) may roam the entire field.
High school games are 48 minutes long, with 12-minute quarters. Each team is given a two-minute break between the first and second quarters, and the third and fourth quarters. Halftime is ten minutes long.
Teams change sides between periods. Each team is permitted two timeouts each half. The team winning the coin toss chooses the end of the field it wants to defend first.
The players take their positions on the field: four in the defensive clearing area, one at the center, two in the wing areas and three in their attack goal area.
Men's lacrosse begins with a face-off. The ball is placed between the sticks of two squatting players at the center of the field. The official blows the whistle to begin play. Each face-off player tries to control the ball. The players in the wing areas can run after the ball when the whistle sounds. The other players must wait until one player has gained possession of the ball, or the ball has crossed a goal area line, before they can release.
Center face-offs are also used at the start of each quarter and after a goal is scored. Field players must use their crosses to pass, catch and run with the ball. Only the goalkeeper may touch the ball with his hands. A player may gain possession of the ball by dislodging it from an opponent's crosse with a stick check. A stick check is the controlled poking and slapping of the stick and gloved hands of the player in possession of the ball.
Body checking is permitted if the opponent has the ball or is within five yards of a loose ball. All body contact must occur from the front or side, above the waist and below the shoulders, and with both hands on the stick. An opponent's crosse may also be stick checked if it is within five yards of a loose ball or ball in the air. Aggressive body checking is discouraged.
If the ball or a player in possession of the ball goes out of bounds, the other team is awarded possession. If the ball goes out of bounds after an unsuccessful shot, the player nearest to the ball when and where it goes out of bounds is awarded possession.
An attacking player cannot enter the crease around the goal, but may reach in with his stick to scoop a loose ball.
A referee, umpire and field judge supervise field play. A chief bench official, timekeepers and scorers assist.