Misjoinder of parties is not ground for dismissal of an action. Parties may be dropped or added by order of the court on motion of any party or of its own initiative at any stage of the action and on such terms as are just. Any claim against a party may be severed and proceeded with separately.
Rule 21.Misjoinder and nonjoinder of parties
Group 4: Parties · Last amended July 1, 1967 · Last verified July 13, 2026
In one sentenceRule 21 makes clear that suing the wrong mix of parties is never grounds to throw out a case, and gives the court broad power to add or drop parties, or split off claims, at any point and on any fair terms.
Full Text of Rule 21
Amendment History
Prior: RPPP Rule 21. Adopted May 5, 1967, effective July 1, 1967.
Plain-English Summary
Rule 21 is short because its job is simple: take the fear out of getting the parties wrong. If a lawsuit names someone who shouldn't be there, or leaves out someone who should, that's not a reason to dismiss the whole case. The court fixes the roster instead.
Any party, or the court on its own, can ask to add or drop parties at any stage of the litigation, and the court sets whatever terms are just when it does. The rule also lets the court sever a claim against one party and let it proceed on its own track, separate from the rest of the case — useful when one claim is ready for trial while others still need discovery, or when combining them would confuse a jury.
Frequently Asked Questions
Can a case be dismissed because the wrong parties were named?
No. Rule 21 says misjoinder of parties is never a ground for dismissing an action. The remedy is to add or drop parties, not to throw the case out.
Who can ask the court to add or drop a party?
Any party can move for it, and the court can also act on its own initiative, at any stage of the case.
What does it mean to sever a claim under Rule 21?
It means the court separates one claim against a party from the rest of the lawsuit so it can proceed independently, effectively becoming its own case for purposes of trial and judgment.
Is there a deadline for fixing misjoined parties?
No. Rule 21 allows the court to add, drop, or sever parties at any stage of the action, not just at the outset.
Source & verification. Rule text and amendment history are
reproduced verbatim from the Washington Superior Court Civil Rules, adopted by the
Supreme Court of Washington. Last verified July 13, 2026. ·
Official source
Also known as: misjoinder of partiesdropping a party from a lawsuitadding a party to a lawsuitsevering claims