An impleader is a civil procedure used by a defending party to bring nonparty into the litigation. A nonparty may be impleaded if the nonparty is or may be liable to the defendant for all or part of the plaintiff’s claim against the defendant. A defendant who impleads a third party is called the "third-party plaintiff”; the impleaded party is the "third-party defendant” It applies only when third party is liable directly to the defendant, not to the plaintiff.
