The referee may issue a caution, in the form of a yellow card, to a player who, in the referee’s judgment, is not playing according to the rules of the game. A card may be issued if the referee finds a player guilty of any of the following:

• unsportsmanlike conduct (including jumping in the stands after a goal)
• disagreeing with an official call
• intentionally delaying the game
• not granting an opponent 10 yards on a free kick
• illegal substitution
• leaving the field of play without permission

A referee may also deem conduct that needs immediate dismissal. These infractions can mean immediate dismissal without a caution:

• violent conduct
• serious foul play (or use of excessive force)
• spitting at anyone
• deliberate hand ball
• a deliberate foul to deny opponent a goal-scoring opportunity
• persistent misconduct

A person receiving a yellow card must be substituted off the field, but can return. A player that gets a red card must leave the field, and the team is not allowed to substitute. A player who gets a second yellow card in the same game is ejected from the game. Two yellow cards in game play equal a red card. In addition to being excluded from participating in the rest of the game, a player who has been sent off may be subject to off-field sanctions. These are usually in the form of suspensions from playing for a number of future games.