Substitution rules for basketball help to eliminate confusion when there is a stoppage of play or when it is half time. Substitution rules clearly outline a procedure that each player must follow before entering the game. As with all rules in basketball, the ones governing substitutions will be enforced by the game officials. Violating the substitution rules will earn your team a warning and then a technical foul.

Checking In

When a player wants to check into the game and substitute himself for another player, he must always communicate with the official game scorer. The official game scorer will be sitting at the scorers table, near half court, and in most cases will be wearing a striped referee's shirt. According to the NCAA rule book, each substitute that desires to enter the game shall give the scorers her uniform number. Giving the official game scorer the number will allow him to easily adjust the score book.

Timeout and Half Time Subsitiutions

According to the NCAA, substitutions between halves shall be reported to the official scorer by the substitutes themselves or a team representative before the signal that ends the intermission. This will allow the official score keeper the chance to adjust the book accordingly before the start of play. During a timeout situation, the NCAA says the player must report to, or be in position to report to, the official scorer before the warning horn and that substitutions will not be permitted after the
warning horn. This rule also helps give time to the official game scorer in an effort to allow her to adjust the score book.

Game Clock Horn

When a substitute has checked in at the scorers table, the time keeper is to buzz the sub into the game at the time of the next dead ball. The horn on the clock that goes off will let the referees know that there is a new player that wants to enter the game. Officially, the NCAA states when entry is at any time other than between halves, and a substitute who is entitled and ready to enter reports to the scorers table, the timers shall sound the game clock horn when the ball is dead and time is stopped.

Legal Substitution

Substitutes may only enter the game when the ball is dead and the clock is stopped, except during the last minute of play in college, and when the clock stops after a made basket in the National Basketball Association. Entering the game at any other time when not beckoned by the officials constitutes a technical foul. In high school, this is penalized by awarding two free throws and possession of the ball to the opposing team. In college, the opposing team simply receives two free throws, and the ball is put back in play to the team who had it last before the technical foul was called. The NBA uses the same rule as college, but only awards one free throw to the opposing team.

Free Throw, Jump Ball and Injury Situations

A player may not substitute for a free throw shooter or jumper---a player participating in a jump ball---unless that player is injured and unable to perform the free throw or jump ball. The player wishing to substitute must wait until the next time the ball is dead and the clock is stopped following the free throw or jump ball in order to substitute. An injured player who is entitled to a jump ball or free throw may be substituted for if she is clearly unable to perform the free throw or jump ball. In high school, the player's coach selects a substitute for the injured player. In college and the NBA, the opposing coach is permitted to choose any member of the opposing team on the bench to substitute for the injured player.