(a) When Defendant May Bring in Third Party. At any time after commencement of the action a defending party, as a third party plaintiff, may cause a summons and complaint to be served upon a person not a party to the action who is or may be liable to the defending party for all or part of the plaintiff's claim against the defending party. The third party plaintiff need not obtain leave to make the service if the third party plaintiff files the third party complaint not later than 10 days after the third party plaintiff serves an original answer. Otherwise the third party plaintiff must obtain leave on motion upon notice to all parties to the action. The person served with the summons and third party complaint, hereinafter called the third party defendant, shall make defenses to the third party plaintiff's claim as provided in rule 12 and counterclaims against the third party plaintiff and cross claims against other third party defendants as provided in rule 13. The third party defendant may assert against the plaintiff any defenses which the third party plaintiff has to the plaintiff's claim. The third party defendant may also assert any claim against the plaintiff arising out of the transaction or occurrence that is the subject matter of the plaintiff's claim against the third party plaintiff. The plaintiff may assert any claim against the third party defendant arising out of the transaction or occurrence that is the subject matter of the plaintiff's claim against the third party plaintiff, and the third party defendant thereupon shall assert defenses as provided in rule 12 and counterclaims and cross claims as provided in rule 13. Any party may move to strike the third party claim, or for its severance or separate trial. A third party defendant may proceed under this rule against any person not a party to the action who is or may be liable to the third party defendant for all or part of the claim made in the action against the third party defendant.
(b) When Plaintiff May Bring in Third Party. When a counterclaim is asserted against a plaintiff, the plaintiff may cause a third party to be brought in under circumstances which under this rule would entitle a defendant to do so.
(c) Tort Cases. This rule shall not be applied in tort cases, to permit the joinder of a liability or indemnity insurance company, unless such company is by statute or contract directly liable to the person injured or damaged.
Wash. Sup. Ct. Civ. R. 14