Rule 14.Third-party practice

Rule 14 gives a defending party a way to pull a nonparty into an ongoing lawsuit, rather than filing a separate action, when that outsider may end up owing the defendant for some or all of what the plaintiff is claiming. The defending party becomes a third-party plaintiff and serves a summons and complaint on the nonparty. Doing this within 14 days of serving the original answer requires no permission, but after that window the third-party plaintiff needs the court's leave.

Once served, the third-party defendant steps into a web of claims and defenses defined by the rule: it must raise defenses under Rule 12 and any compulsory counterclaim under Rule 13(a) against the third-party plaintiff, may raise permissive counterclaims or crossclaims against other third-party defendants, may assert against the plaintiff any defense the third-party plaintiff has, and may bring its own claim against the plaintiff arising from the same transaction or occurrence. The plaintiff, in turn, may assert a related claim directly against the third-party defendant, who then owes the same defense and counterclaim obligations back to the plaintiff. Any party can move to strike, sever, or separately try the third-party claim, and a third-party defendant facing its own liability exposure can repeat the same process against a further nonparty. A plaintiff who becomes a defendant to a counterclaim gets the same third-party practice available to an original defendant.