Rule 21 Federal Rules of Civil Procedure
Rule 21 of the Federal Rules of Civil Procedure is about Misjoinder and Nonjoinder of Parties. It is under Title IV (Parties) of the Rules.
Misjoinder of parties is not a ground for dismissing an action. On motion or on its own, the court may at any time, on just terms, add or drop a party. The court may also sever any claim against a party.