(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
(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
(A) any right to relief is asserted against them jointly, severally, or in the alternative with respect to or arising out of
(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
R20(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.
(a) Consolidation. If actions before the court involve a common question of law or fact, the court may:
(1) join for hearing or trial any or all matters at issue in the actions;
(2) consolidate the actions; or
(3) issue any other orders to avoid unnecessary cost or delay.
(b) Separate Trials. For convenience, to avoid prejudice, or to expedite and economize, the court may order a separate trial of one or more separate issues, claims, cross-claims, counterclaims, or third-party claims. When ordering a separate trial, the court must preserve any federal right to a jury trial.
(a) Persons Required to Be Joined if Feasible.
(1) Required Party. A person who is subject to service of process and whose joinder will not deprive the court of subject-matter jurisdiction must be joined as a party if:
(A) in that person's absence, the court cannot accord complete relief among existing parties; or
(B) that person claims an interest relating to the subject of the action and is so situated that disposing of the action in the person's absence may:
(i) as a practical matter impair or impede the person's ability to protect the interest; or
(ii) leave an existing party subject to a substantial risk of incurring double, multiple, or otherwise inconsistent obligations because of the interest.
(2) Joinder by Court Order. If a person has not been joined as required, the court must order that the person be made a party. A person who refuses to join as a plaintiff may be made either a defendant or, in a proper case, an involuntary plaintiff.
(3) Venue. If a joined party objects to venue and the joinder would make venue improper, the court must dismiss that party.
(b) When Joinder Is Not Feasible. If a person who is required to be joined if feasible cannot be joined, the court must determine whether, in equity and good conscience, the action should proceed among the existing parties or should be dismissed. The factors for the court to consider include:
(1) the extent to which a judgment rendered in the person's absence might prejudice that person or the existing parties;
(2) the extent to which any prejudice could be lessened or avoided by:
(A) protective provisions in the judgment;
(B) shaping the relief; or
(C) other measures;
(3) whether a judgment rendered in the person's absence would be adequate; and
(4) whether the plaintiff would have an adequate remedy if the action were dismissed for nonjoinder.
(c) Pleading the Reasons for Nonjoinder. When asserting a claim for relief, a party must state:
(1) the name, if known, of any person who is required to be joined if feasible but is not joined; and
(2) the reasons for not joining that person.
(d) Exception for Class Actions. This rule is subject to Rule 23.
(a) Intervention of Right. On timely motion, the court must permit anyone to intervene who:
(1) is given an unconditional right to intervene by a federal statute; or
(2) claims an interest relating to the property or transaction that is the subject of the action, and is so situated that disposing of the action may as a practical matter impair or impede the movant's ability to protect its interest, unless existing parties adequately represent that interest.
(b) Permissive Intervention.
(1) In General. On timely motion, the court may permit anyone to intervene who:
(A) is given a conditional right to intervene by a federal statute; or
(B) has a claim or defense that shares with the main action a common question of law or fact.
(2) By a Government Officer or Agency. On timely motion, the court may permit a federal or state governmental officer or agency to intervene if a party's claim or defense is based on:
(A) a statute or executive order administered by the officer or agency; or
(B) any regulation, order, requirement, or agreement issued or made under the statute or executive order.
(3) Delay or Prejudice. In exercising its discretion, the court must consider whether the intervention will unduly delay or prejudice the adjudication of the original parties' rights.
(c) Notice and Pleading Required. A motion to intervene must be served on the parties as provided in Rule 5. The motion must state the grounds for intervention and be accompanied by a pleading that sets out the claim or defense for which intervention is sought.