Rule 20.Permissive joinder of parties.

Last verified July 1, 2026

In one sentenceRule 20 lets multiple plaintiffs join together, or multiple defendants be joined together, whenever their claims arise from the same transaction or occurrence and share a common question of law or fact, while giving the court power to order separate trials or other protective measures so joinder does not unfairly burden any party.

Full Text of Rule 20

Text sizeJump to: (a) (b)

(a) Persons who may join or be joined.

(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.

End

Amendment History

Promulgated by R-16-0010, effective January 1, 2017.

Plain-English Summary

Rule 20 allows plaintiffs to combine their claims in a single lawsuit, or a plaintiff to name multiple defendants, when the claims arise out of the same transaction, occurrence, or series of related events and share at least one common question of law or fact. Neither requirement demands identical claims — the rule allows relief asserted jointly, severally, or in the alternative, and the court can enter judgment for or against only the parties entitled to or liable for it, without needing everyone joined to win or lose together.

To keep permissive joinder from becoming unfair, the court can issue protective orders, including ordering separate trials, when including a party who has no real stake in a particular claim would cause embarrassment, delay, or added expense to someone else in the case.

Frequently Asked Questions

What must plaintiffs or defendants share to be joined together under Rule 20?

Claims arising from the same transaction, occurrence, or series of related events, plus a common question of law or fact.

Do all joined plaintiffs need to win or lose together?

No, the court can grant judgment to some plaintiffs and against some defendants according to each one’s own rights or liabilities.

What can a court do if joinder becomes unfair to one party?

Order separate trials or other protective measures to prevent embarrassment, delay, or added expense.

Source & verification. The rule text and History are reproduced verbatim from the official Arizona Rules of Civil Procedure (Ariz. R. Civ. P. 20). Prescribed by the Supreme Court of Arizona (Ariz. Const. art. 6, § 5). The plain-English summary is original and written by us. Last verified July 1, 2026. · Official source

Also known as: permissive joinderjoinder of partiessame transaction or occurrence