A guide to drafting an Ohio state court pleading in which a civil defendant asserts claims against a person not yet party to the action who is allegedly liable to the defendant for any liability it incurs on the plaintiff's claim. These "third-party claims" may seek indemnification, contribution, or similar relief. This Practice Note explains the nature of third-party claims under the Ohio Civil Rules (Ohio Civ. R.), considerations in deciding whether to plead them, and how to draft, serve, and file them in an Ohio court of common pleas. Finally, this Note addresses answers to these claims, replies to the answers, and claims directly between the plaintiff and the third-party defendant.