In indoor volleyball, each team has six players on the court at all times. A team can substitute players on the bench for players on the court, but it must follow the substitution rules. Failure to follow substitution rules will result in penalties against your team, such as a lost time-out. This article addresses the rules of the United States Association of Volleyball (USAV), a member organization of the International Federation of Volleyball (FIVB). The official USAV rules for domestic competition vary slightly from FIVB rules. Other organizations, such as the United States National Collegiate Athletic Association (NCAA), follow different rules.
Section 15.6 of the USAV rule book states that each team can make 12 substitutions per set. The USAV rule book suggests this deviation from the FIVB rules to promote continuity of play in domestic competition. The FIVB rules dictate that teams can make only 6 substitutions per set. The USAV domestic competition rules allow teams to substitute the same player multiple times within a set as long as the teams do not exceed their 12-substitution limit. Players can only reenter the game in their original positions within the team's rotation.
The Libero position has existed in volleyball since 1998. Section 19 of the USAV domestic competition rule book outlines the rules regarding the Libero position. Each team can designate two Libero players. The Libero player, a defensive specialist, must remain in the back row throughout the game and cannot serve, attack or block the ball. Substitutions involving the Libero player do not count toward a team's substitution count per set. Teams can substitute the Libero in and out of the game an unlimited number of times. The Libero can only replace a back row player.
Players entering or leaving the court during a regular substitution must cross the sideline between the attack line and the scorer's table. The Libero player must enter and leave the court between the attack line and the court's end line.
A team can request a substitution at the start of a set or during a time-out. You can substitute more than one player at a time. The referee must authorize all substitutions and the scorer must record them. A team can make a Libero substitution before the start of a set, during a time-out or before the service whistle.