Substitutions and rotation decide who may be where.

How rotation works

1. Each team submits a lineup order before the set, placing six players into six rotational positions.
2. The serving order follows that rotation for the whole set unless a legal substitution changes the player occupying a slot.
3. When the receiving team wins the right to serve, its players rotate one position clockwise before the next serve.
4. At service contact, each player must be in the correct relative position for that rotation.
5. After the serve is contacted, players may move into their preferred offensive or defensive roles, subject to back-row and libero restrictions.

What a legal substitution changes

• The player changes, not the slot: the substitute takes the replaced player's rotation position and service-order place.
• The ball must normally be dead: substitutions are handled between rallies under the procedure used by the competition.
• Entry limits vary: FIVB indoor rules use a strict team limit of six substitutions per set, while school, college, and national codes may allow different totals.
• Re-entry rules matter: many codes restrict a starter and substitute to the same lineup position when they leave and return.
• Injury exceptions are separate: exceptional substitutions may be available when a player cannot continue, but the referee applies the specific code's procedure.

Libero replacements are different

A libero replacement is usually not counted as a regular substitution. The libero replaces a back-row player through the code's libero procedure, and the replacement follows that back-row rotational slot. That is why a libero can enter and leave often without using the team's normal substitution count, but still cannot ignore libero attack, blocking, or service restrictions.

Rotation is not the same as court role

A setter can begin in the back row, a middle blocker can be replaced by a libero, and an outside hitter can receive serve from a stacked position. Those tactical roles are legal only if the underlying rotation is legal at service contact and each player keeps the restrictions attached to that rotational status.

What officials check first

• Wrong server: the player serving is not the next player due in the service order.
• Position fault or overlap: players are in the wrong relative positions at the instant of service contact.
• Illegal substitution: the entry breaks the substitution limit, re-entry rule, lineup position rule, or procedure in the code being used.
• Illegal libero replacement: the libero enters, leaves, serves, or replaces a player in a way the applicable rules do not allow.

Where the details can vary

This page describes standard six-player indoor volleyball. Beach volleyball, recreational leagues, youth modifications, and local tournament rules may use different substitution limits or rotation procedures. For formal matches, the lineup sheet, scorekeeper, second referee, and competition rulebook control the final answer.

A substitute serves from the wrong spot

The question is not only whether the player was legally substituted. Officials also check whether that lineup slot was actually due to serve. A player can enter legally but still create a wrong-server fault if the team loses track of the rotation order.

A team stacks after a substitution

Stacking is legal when the players preserve the required left-right and front-back relationships until service contact. A substitution does not give the team a new formation shortcut; the new player must stand legally for the same rotational slot as the player they replaced.

Next volleyball topics

• Rotation and overlap
• Positions and roles
• Libero and back-row attacks
• Serving faults and let serves
• Back to volleyball overview

Source material

• FIVB Official Volleyball Rules
• FIVB Basic Rules
• NCAA Playing Rules
• NFHS Volleyball Rules