Federal Rule of Civil Procedure 20
Rule 20. Permissive Joinder of Parties
(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—as well as a vessel, cargo, or other property subject to admiralty process in rem—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
- Unlike Rule 19 which concerns compulsory party joinder, Rule 20 applies to permissive joinder of parties. That is, a claim is brought by a plaintiff against multiple defendants and/or multiple plaintiffs bring claims against a defendant or defendants.
- The Federal Rules make this pretty easy.
- Parties can join together to make the same claim provided (i) their claim arises out of the same transaction or occurrence (or series of transactions and occurrences); and (ii) there is a common question of law or fact to all the plaintiffs.
- For example, let’s say many US footballer players suffered head injuries. The could all sue the NFL together. Our caption might look something like this but you can imagine dozens more plaintiffs:
- When many plaintiff sue together or where many defendants are being sued don’t make the mistake of thinking the case must be a class action. Each party is raising its own claim but for reasons of efficiency the Federal Rules encourage the parties to bring their cases in the same lawsuit.
- Judges may, in their discretion, sever trials so the same parties are not being tried together.
- You will often see parties joined together in so-called mass tort litigation where many plaintiffs allegedly suffered injuries that result from a defendant’s tortious conduct.