Rule 1-015. Amended and supplemental pleadings.

A. Amendments. A party may amend its pleading once as a matter of course at any time before a responsive pleading is served or, if the pleading is one to which no responsive pleading is permitted and the action has not been placed on the trial calendar, the party may amend it at any time within twenty (20) days after it is served. Otherwise a party may amend its pleading only by leave of court or by written consent of the adverse party, and leave shall be freely given when justice requires. A party shall plead in response to an amended pleading within the time remaining for response to the original pleading or within ten (10) days after service of the amended pleading, whichever period may be the longer, unless the court otherwise orders. B. Amendments to conform to the evidence. When issues not raised by the pleadings are tried by express or implied consent of the parties, they shall be treated in all respects as if they had been raised in the pleadings. Amendment of the pleadings as may be necessary to cause them to conform to the evidence and to raise these issues may be made on motion of any party at any time, even after judgment; but failure to amend does not affect the result of the trial of these issues. If evidence is objected to at the trial on the ground that it is not within the issues made by the pleadings, the court may allow the pleadings to be amended and shall do so freely when the presentation of the merits of the action will be subserved thereby and the objecting party fails to satisfy the court that the admission of the evidence would prejudice it in maintaining its action or defense on the merits. The court may grant a continuance to enable the objecting party to meet the evidence. C. Relation back of amendments. (1) Whenever the claim or defense asserted in the amended pleading arose out of the conduct, transaction, or occurrence set forth or attempted to be set forth in the original pleading, the amendment relates back to the date of the original pleading. (2) When a party files a motion to amend a pleading prior to the running of the statute of limitations, changing the party against whom a claim is asserted, a ruling granting the motion relates back to the date the motion was filed if the motion was accompanied by a proposed amended pleading naming the new party. (3) When a party files a motion to amend a pleading after the statute of limitations has run, changing the party against whom a claim is asserted, a ruling granting the motion relates back to the date of the original pleading if Paragraph (C)(1) of this rule is satisfied and, within the period provided by Rule 1-004(C)(2) NMRA for serving process, the party to be brought in by amendment (a) has received such notice of the institution of the action that it will not be prejudiced in maintaining its defense on the merits; and (b) knew or should have known that, but for a mistake concerning the identity of the proper party, the action would have been brought against it. D. Supplemental pleadings. On motion of a party, the court may, on reasonable notice and on terms as are just, permit the party to serve a supplemental pleading setting forth transactions, occurrences, or events which have happened since the date of the pleading sought to be supplemented. Permission may be granted even though the original pleading is defective in its statement of a claim for relief or defense. If the court deems it advisable that the adverse party plead to the supplemental pleading, it shall so order, specifying the time therefor. E. All matters set forth in one pleading. In every complaint, answer, or reply, amendatory or supplemental, the party shall set forth in one entire pleading all matters which, by the rules of pleading, may be set forth in the pleading, and which may be necessary to the proper determination of the action or defense.