(a) Permissive Joinder. All persons may join in one action as plaintiffs if they assert any right to relief jointly, severally, or in the alternative in respect of or arising out of the same transaction, occurrence, or series of transactions or occurrences and if any question of law or fact common to all these persons will arise in the action. All persons may be joined in one action as defendants if there is asserted against them jointly, severally, or in the alternative, any right to relief in respect of or arising out of the same transaction, occurrence, or series of transactions or occurrences and if any question of law or fact common to all defendants will arise in the action. A plaintiff or defendant need not be interested in obtaining or defending against all the relief demanded. Judgment may be given for one or more of the plaintiffs according to their respective right to relief, and against one or more defendants according to their respective liabilities.
Rule 20.Permissive Joinder of Parties
Current through June 1, 2026 · Last verified July 10, 2026
In one sentenceRule 20 lets multiple plaintiffs sue together or multiple defendants be sued together whenever their claims arise from the same transaction or occurrence and share a common question of law or fact, while giving the court tools to separate parties or claims that would cause unfair prejudice.
Full Text of Rule 20
(b) Separate Trials. The court may make such orders as will prevent a party from being embarrassed, delayed, or put to expense by the inclusion of a party against whom he asserts no claim and who asserts no claim against him, and may order separate trials or make other orders to prevent delay or prejudice.
(c) Parties Jointly or Severally Liable. Persons jointly or severally liable upon the same obligation or instrument, including the parties to negotiable instruments and sureties on the same or separate instruments, may all or any of them be sued in the same action, at the option of the plaintiff.
Amendment History
The source reproduced here (current through June 1, 2026) records no amendment to this rule since its original adoption — no Credits line appears for it in the compiled rules. For the underlying adopting order and any later amendments, see the Colorado General Assembly.
Plain-English Summary
Rule 20 sets the test for putting more than one plaintiff or more than one defendant into a single lawsuit. Plaintiffs can join together if they assert rights arising out of the same transaction, occurrence, or series of transactions or occurrences, and if their claims share at least one common question of law or fact. The same test applies to joining multiple defendants. No plaintiff or defendant has to be interested in every form of relief sought in the case, and the court enters judgment for and against each party according to that party's own rights and liabilities.
Because Rule 20 can pull in parties with limited connection to each other, subsection (b) gives the court authority to order separate trials, or make other orders, to keep a party from being embarrassed, delayed, or forced to spend money defending claims that do not involve them. Subsection (c) confirms that people jointly or severally liable on the same obligation or instrument — including parties to negotiable instruments and their sureties — can be sued together in one action at the plaintiff's choice, even when they are liable on separate instruments.
Frequently Asked Questions
Can several plaintiffs with different injuries sue the same defendant together?
Yes, if their claims arise from the same transaction, occurrence, or series of occurrences and share a common question of law or fact, Rule 20 lets them join as co-plaintiffs.
What can I do if I'm sued alongside a defendant I have nothing to do with?
Rule 20(b) lets the court order separate trials or other relief to prevent a party from being delayed, embarrassed, or put to needless expense by an unrelated co-defendant.
Can I sue everyone who signed a promissory note in the same lawsuit?
Yes. Rule 20(c) allows a plaintiff to sue all or any parties jointly or severally liable on the same obligation or instrument, including negotiable instruments and their sureties, in one action.
Does joining defendants under Rule 20 mean they're all liable for the same amount?
No. Rule 20(a) directs the court to enter judgment for and against each party according to that party's own right to relief or liability.
Source & verification. The rule text is reproduced verbatim from the
official Colorado Rules of Civil Procedure (Colo. R. Civ. P. 20). Prescribed by the Supreme Court of Colorado (C.R.S. § 13-2-108; Colo. Const. art. VI). The plain-English summary is original and written by us. Last verified July 10, 2026. ·
Official source
Also known as: permissive joinder of partiessuing multiple defendants togethermultiple plaintiffs one lawsuitCRCP 20joint and several liability lawsuitseparate trials same case