What document initiates a separate claim by a defendant against a third party or nonparty?

• A. Third-party complaint
• B. Affidavit of Service
• C. Personal Service
• D. Substituted service

Answer: (A)

When a defendant believes another person or entity may be liable to the plaintiff, they can bring that person into the case by filing a third-party complaint. This document starts a separate claim against the third party (a nonparty to the original action), allowing the defendant to seek relief or a share of any damages from them. In New York practice, this is known as third-party practice or impleader, and it keeps the plaintiff in the action while adding the new party who may be responsible for part or all of the plaintiff’s claim.

The other terms are about serving papers, not starting a new claim. An affidavit of service is a sworn statement that service of process occurred. Personal service and substituted service describe methods of delivering the summons and complaint to the parties. These are mechanics of getting papers to people, not the pleading that initiates a new cause of action against a third party.