Players use the flat face of their sticks to hit and dribble the ball down the pitch and attempt to shoot it past a goalkeeper and into their opponent's goal cage. Only shots taken within the striking circle count. The ball cannot be kicked, held or carried by field players. There is no offside in field hockey.
The winner of a coin toss chooses either a) which goal to attack in the first half, or b) to start play with a center pass. The direction of play and ball possession is reversed in the second half. Play in each half begins with the center pass, when a player hits the ball in any direction from the center of the field while each team is positioned on its half of the pitch. The center pass is also used after goals are scored.
Each team is allowed 11 players on the field, including the goalkeeper. Rosters are 16 players, maximum. Substitutions are allowed.
In field hockey, goals are worth one point. The team with the most goals at the end of the match is declared the winner. In order to be officially tallied, a scoring shot must be taken within the striking circle; a ball struck from outside the scoring circle that is deflected into the goal counts.
As of the Rio Games, Olympic field hockey matches are divided into four 15-minute quarters. Previously, matches consisted of two 35-minute halves.
There are 40-second timeouts when a penalty corner is awarded.
In pool play, if there is a tied at the end of a match, it ends in a draw. Both teams receive one point for the result.
For the first time at the Olympics, in matches that require a winner -- quarterfinals, semifinals, and medal matches -- if there is a tie at the end of regulation, the teams will have a shootout to determine the winner without an overtime period. Each team selects five players to take alternating penalty strokes against the opposing goalkeeper. If the score is still tied after the first round of penalty strokes, the same shooters will take another series of penalty strokes. This time, however, the game goes into a sudden death format. The first team to score more goals than the opposing team after an equal number of strokes wins.
A player is not allowed to:
- Shield or obstruct the ball from an opponent with the body or stick. All players must have an equal chance to gain control of the ball as it is dribbled or passed down the field.
- Play the ball with the rounded side of the stick.
- Interfere in the game without a stick.
- Charge, hit, shove or trip an opponent.
- Play the ball in a potentially dangerous way.
- Use the foot or leg to support the stick in order to resist an opponent.
- Raise the stick in a dangerous or intimidating manner while approaching, attempting to play or stop the ball.
- Advance the ball by any means other than with the stick.
- Stop or deflect the ball in the air or on the ground with any part of the body.
- Hit, hook, hold or interfere with an opponent's stick.
The penalties for each foul vary depending on where they are committed:
- If a foul is committed outside the shooting zone, a free hit is given to the non-offending team.
- If a defender intentionally hits the ball across his or her back line, commits a foul within the shooting circle, or intentionally commits a foul within the 25-yard area, a penalty corner is awarded to the attacking team.
- If an intentional foul is committed inside the shooting circle against an opponent with the ball or a chance to play the ball, or a foul is committed to prevent a goal, a penalty stroke is awarded to the attacking team.
Substitutions are allowed in field hockey. There is no limit to the number of players who may be substituted at one time, nor is there a limit to the number of times any player may substitute or be substituted for. Substitutions are allowed at any time during a match, except during penalty corners (unless the defending goalkeeper is injured or suspended).
For rough or dangerous play, misconduct or any intentional offense, the umpire may:
- Caution the offending player
- Warn the offending player with a green card.
- Temporarily suspend the offending player for a minimum of five minutes with a yellow card. While a player is suspended, the team must play shorthanded.
- Permanently suspend the offending player for the match with a red card.
Two umpires on the field officiate each match. An additional umpire may sit at the scorer's table. The field umpires monitor tough or dangerous play, misconduct or any intentional offenses. Umpires are also responsible for keeping a written record of goals scored or awarded, and of warning or suspension cards issued.