Third-party complaint

(a) If the defendant alleges that another person, who is not named as a party in the case, is wholly or partially responsible for the damages set forth in the complaint, the defendant may file a third-party complaint against such person. No filing fee shall be required. (b) A third-party summons and complaint shall be served upon the third-party defendant in the same manner as an initial summons and complaint. A third-party complaint shall be answered in the same manner as is provided by Rule 4.