Impleader
（重定向自Implead）
Impleader is a procedural device before trial in which one party joins a third party into a lawsuit because that third party is liable to an original defendant. Using the vocabulary of the Federal Rules of Civil Procedure, the defendant seeks to become a third-party plaintiff by filing a third party complaint against a third party not presently party to the lawsuit, who thereby becomes a third-party defendant. This complaint alleges that the third party is liable for all or part of the damages that the original plaintiff may win from the original defendant.