Group IV: Parties · Last amended March 1, 2017 · Last verified July 14, 2026
In one sentenceRule 20 lets multiple plaintiffs sue together or multiple defendants be sued together when their claims arise from the same transaction or occurrence and share a common question of law or fact.
(1)Plaintiffs. — Persons may join in one action as plaintiffs if:
(A)they assert any right to relief jointly, severally, or in the alternative with respect to or arising out of the same transaction, occurrence, or series of transactions or occurrences; and
(B)any question of law or fact common to all plaintiffs will arise in the action.
(2)Defendants. — Persons may be joined in one action as defendants if:
(A)any right to relief is asserted against them jointly, severally, or in the alternative with respect to or arising out of the same transaction, occurrence, or series of transactions or occurrences; and
(B)any question of law or fact common to all defendants will arise in the action.
(3)Extent of Relief. — Neither a plaintiff nor a defendant need be interested in obtaining or defending against all the relief demanded. The court may grant judgment to one or more plaintiffs according to their rights, and against one or more defendants according to their liabilities.
(b)Protective Measures. — The court may issue orders — including an order for separate trials — to protect a party against embarrassment, delay, expense, or other prejudice that arises from including a person against whom the party asserts no claim and who asserts no claim against the party.
Amendment History
Added February 2, 2017, effective March 1, 2017.
Plain-English Summary
Rule 20 lets people join together as plaintiffs, or be joined together as defendants, when two things line up: their claims arise from the same transaction, occurrence, or series of events, and the case will raise at least one common question of law or fact. Neither test demands identical claims — plaintiffs can seek relief jointly, individually, or as alternatives to each other, and the same goes for claims against multiple defendants. No plaintiff has to want everything the others are asking for, and no defendant has to be on the hook for everything alleged against the others; the court sorts out judgment according to each party's own rights and liabilities.
Joining several plaintiffs or defendants in one case can create friction for someone who has little stake in claims that don't involve them. Rule 20 lets the court step in with protective measures — including ordering separate trials — to shield a party from the embarrassment, delay, or added expense that can come from being bundled into a case alongside claims that have nothing to do with them.
Frequently Asked Questions
Can unrelated plaintiffs join together in one lawsuit?
No. Their claims must arise from the same transaction, occurrence, or series of events, and the case must raise at least one common question of law or fact shared by all of them.
What do plaintiffs or defendants need in common to be joined under Rule 20?
They need claims tied to the same transaction, occurrence, or series of transactions, plus at least one shared question of law or fact.
Does every plaintiff have to want the same relief?
No. Plaintiffs can seek relief jointly, individually, or as alternatives to one another, and the court sorts out judgment according to each party's own rights and liabilities.
What can a defendant do if being joined with other defendants is unfair?
The court can order protective measures, including separate trials, to shield a defendant from delay, expense, or embarrassment caused by claims that do not involve them.
What is the difference between Rule 20 and Rule 19?
Rule 20 covers parties who may choose to join a case together. Rule 19 covers parties who must be joined because the case cannot proceed properly without them.
Source & verification. Rule text and amendment history are
reproduced verbatim from the Wyoming Rules of Civil Procedure, adopted by the
Supreme Court of Wyoming. Last verified July 14, 2026. ·
Official source
Also known as:permissive joinder wyomingmultiple plaintiffs one lawsuitjoining defendants same casemass tort joinder rule