(a) Defendant's Claim Against Third Party. A defendant, as a third-party plaintiff, may cause a summons and complaint, together with a copy of all pleadings, scheduling notices, court orders, and other papers previously filed in the action, to be served upon a person not a party to the action who is or may be liable to the defendant for all or part of a plaintiff's claim against the defendant. A person so served becomes a third-party defendant.

(b) Response by Third Party. A third-party defendant shall file a notice of intention to defend pursuant to Rule 3-307 and may assert counterclaims against the third-party plaintiff and cross-claims against other third-party defendants as provided by Rule 3-331. The third-party defendant may assert against the plaintiff any defenses that 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.

(c) Plaintiff's Claim Against Third Party. The plaintiff shall 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 file a notice of intention to defend pursuant to Rule 3-307 and may assert counterclaims and cross-claims as provided by Rule 3-331. If the plaintiff fails to assert any such claim against the third-party defendant, the plaintiff may not thereafter assert that claim in a separate action instituted after the third-party defendant has been impleaded. This section does not apply when a third-party claim has been stricken pursuant to section (e) of this Rule.

(d) Additional Parties. A third-party defendant may proceed under this Rule against any person who is or may be liable to the third-party defendant for all or part of the claim made in the pending action. When a counterclaim is asserted against a plaintiff, the plaintiff may cause a third party to be brought in under circumstances that would entitle a defendant to do so under this Rule.

(e) Time for Filing. A defendant may file a third-party claim at any time before ten days of the scheduled trial date. Within ten days of the scheduled trial date or after trial has commenced, a defendant may file a third-party claim only with the consent of the plaintiff or by order of court.

Source: This Rule is derived as follows:

Section (a) is derived from former M.D.R. 315 a and b.

Section (b) is derived from former M.D.R. 302 a.

Section (c) is derived from former Rule 315 d.

Section (d) is derived from former Rule 315 f 1 and 2.

Section (e) is derived from former M.D.R. 315 a.