A Practice Note explaining how a defendant in a Texas district or county court civil action may assert a claim against a nonparty that is or may be liable to the defendant or the plaintiff for the plaintiff's claim. This Practice Note explains the nature of these third-party claims (also known as impleader) under Texas law and how to draft, file, and serve third-party petitions. This Note also addresses how to answer or otherwise respond to third-party claims, how to reply to third-party answers, and how to plead additional claims that may arise between the original plaintiff and the third-party defendant.