How many substitutions are allowed per set in volleyball?

FIVB allows 6 substitutions per team per set. NFHS (high school) allows 18 substitutions per set. NCAA allows 15 substitutions per set. Libero replacements never count as substitutions.

Full Explanation

Per FIVB Rule 15.5.1, each team is allowed a maximum of 6 substitutions per set. A substitute player may only enter the game in the position of the player they replace, and that same player must re-enter to replace the substitute if a re-substitution is needed. Under NFHS rules, each team is allowed 18 substitutions per set (NFHS Rule 10-3). Under NCAA rules, each team is allowed 15 substitutions per set. Under USAV domestic rules, 12 substitutions are allowed per set for most competition levels. Libero replacements are not counted as substitutions under any ruleset.

Rulesets covered: FIVB/USAV/NFHS/NCAA  |  Rule Reference: FIVB Rule 15.5.1; NFHS Rule 10-3; NCAA Rule 10