Joinder of Claims and Parties, Impleader, Intervention, Interpleader

Joinder of Claims and Parties (Rules 18, 20, 13)

Joinder of claims (Rule 18)

Once a party has one proper claim against an opposing party, Rule 18 lets it join any additional claims it has against that party — related or not. Joinder under Rule 18 is permissive, but each joined claim still needs an independent jurisdictional basis (federal question, diversity, or supplemental jurisdiction).

Permissive party joinder (Rule 20)

Rule 20 lets plaintiffs join together, or sue multiple defendants together, when both are satisfied:

1. The claims arise out of the same transaction or occurrence (or series), AND
2. There is a common question of law or fact.

Counterclaims and cross-claims (Rule 13)

Trap: A compulsory counterclaim usually qualifies for supplemental jurisdiction (same transaction = common nucleus), so it needs no independent basis; a permissive counterclaim usually does.

Required Parties and Impleader (Rules 19, 14)

Compulsory / required-party joinder (Rule 19)

Rule 19 identifies parties who must be joined if feasible. The analysis has three steps:

1. Is the absentee 'required' (19(a))? Yes if (a) the court cannot accord complete relief among existing parties without it, OR (b) the absentee claims an interest that would be impaired by its absence, or that exposes an existing party to double or inconsistent obligations.
2. Is joinder feasible? Joinder is infeasible if it would destroy SMJ (e.g., break complete diversity) or the court lacks PJ over the absentee.
3. If not feasible, is the party indispensable (19(b))? The court weighs prejudice, whether it can be lessened, adequacy of a judgment without the party, and whether the plaintiff has an adequate remedy if dismissed. If indispensable, the action must be dismissed.

Impleader / third-party practice (Rule 14)

Rule 14 lets a defending party (as a 'third-party plaintiff') bring in a non-party who 'is or may be liable to it for all or part of' the original claim — a derivative liability theory such as indemnity or contribution.

• The defendant may implead as of right within 14 days of serving its answer; later requires leave of court.
• The third-party claim is supported by supplemental jurisdiction; recall that 1367(b) bars a plaintiff from asserting claims against a Rule 14 third party if doing so would defeat complete diversity.
• Trap: Impleader is NOT for saying 'the third party, not me, is liable to the plaintiff' — it requires the third party's liability to be derivative of the defendant's liability.

Intervention and Interpleader (Rules 24, 22; 28 U.S.C. 1335)

Intervention (Rule 24)

Intervention lets a non-party inject itself into pending litigation.

• Intervention of right (24(a)): the applicant must show (1) a timely application, (2) an interest in the subject matter, (3) that disposition may impair that interest, and (4) the interest is not adequately represented by existing parties.
• Permissive intervention (24(b)): allowed at the court's discretion when the applicant's claim/defense shares a common question with the main action and intervention won't unduly delay or prejudice.

Interpleader (Rule 22 and statutory)

Interpleader lets a stakeholder holding property/funds claimed by two or more adverse claimants force them to litigate their competing claims in one action, protecting the stakeholder from multiple liability.

California distinctions

California joinder largely parallels the federal rules but uses different vocabulary: cross-complaints (CCP 428.10) serve the role of both counterclaims and cross-claims, and a cross-complaint against the plaintiff arising from the same transaction is effectively compulsory under CCP 426.30. California also provides for interpleader (CCP 386) and intervention (CCP 387) with standards similar to the federal model.

Joinder and the supplemental-jurisdiction overlay

Every joined claim or party in federal court still needs a jurisdictional hook, so joinder and supplemental jurisdiction (28 U.S.C. 1367) must be analyzed together. A defendant's Rule 14 third-party claim, a Rule 13(g) cross-claim, and a compulsory counterclaim all typically qualify for supplemental jurisdiction because they arise from the same transaction (common nucleus).

But recall the 1367(b) carve-out: in a case anchored on diversity, a plaintiff may not assert supplemental claims against persons joined under Rules 14, 19, 20, or 24 if doing so would break complete diversity. Trap: the 1367(b) limit is plaintiff-specific — it never restricts defendants — and it applies only when the anchor is diversity, not federal question.

Worked Rule 19 hypothetical: A and B co-own a contract; the obligor performs to A only, and B sues for breach in federal court. If A is a non-diverse party whose absence risks the obligor facing double liability, A is a required party under 19(a). If joining A would destroy complete diversity (infeasible) and A is indispensable under the 19(b) factors, the court must dismiss — 'in equity and good conscience' the action cannot proceed without A.