Okla. Stat. tit. 12, § 12-2015

AMENDED AND SUPPLEMENTAL PLEADINGS

A. AMENDMENTS. A party may amend his or her 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 upon the trial

calendar, he or she may so amend it at any time within twenty (20)

days after it is served. Amendments to add omitted counterclaims or

to add or drop parties may be made as a matter of course within the

time specified above. Otherwise a party may amend the pleading only

by leave of court by submitting the proposed amendment with the

motion for leave of court or by written consent of the adverse

party; and leave shall be freely given when justice so requires. A

party shall respond to an amended pleading within the time remaining

for response to the original pleading or within twenty (20) days

after the service of the amended pleading, whichever period may be

longer, unless the court otherwise orders.

B. AMENDMENTS TO CONFORM TO THE EVIDENCE. When issues not

raised by the pleadings or by the pretrial conference order, where

the order has superseded the pleadings, are tried by express or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 or the pretrial

conference order. Such amendment as may be necessary to cause the

pleadings or the pretrial conference order to conform to the

evidence and to raise these issues may be made upon motion of any

party at any time, even after judgment; but failure so 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 or the pretrial conference order, the

court may allow the pleadings or the pretrial conference order to be

amended and shall do so freely when the presentation of the merits

of the action will be served thereby and the objecting party fails

to satisfy the court that the admission of such evidence would

prejudice him or her in maintaining the action or defense upon the

merits. The court may grant a continuance to enable the objecting

party to meet such evidence.

Oklahoma Statutes - Title 12. Civil Procedure Page 414

Where the pretrial conference order has superseded the

pleadings, it is sufficient to amend the order and the pleadings

shall not be amended.

C. RELATION BACK OF AMENDMENTS. An amendment of a pleading

relates back to the date of the original pleading when:

1. Relation back is permitted by the law that provides the

statute of limitations applicable to the action; or

2. 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; or

3. The amendment changes the party or the naming of the party

against whom a claim is asserted if paragraph 2 of this subsection

is satisfied and, within the period provided by subsection I of

Section 2004 of this title for service of the summons and petition,

the party to be brought in by amendment:

a. has received such notice of the institution of the

action that he or she will not be prejudiced in

maintaining a 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 him or her.

An amendment to add an omitted counterclaim does not relate back to

the date of the original answer.

The delivery or mailing of process to the Attorney General of

Oklahoma, or an agency or officer who would have been a proper

defendant if named, satisfies the requirements of subparagraphs a

and b of this paragraph with respect to the State of Oklahoma or any

agency or officer thereof to be brought into the action as a

defendant.

D. SUPPLEMENTAL PLEADINGS. Upon motion of a party the court
.

The delivery or mailing of process to the Attorney General of

Oklahoma, or an agency or officer who would have been a proper

defendant if named, satisfies the requirements of subparagraphs a

and b of this paragraph with respect to the State of Oklahoma or any

agency or officer thereof to be brought into the action as a

defendant.

D. SUPPLEMENTAL PLEADINGS. Upon motion of a party the court

may, upon reasonable notice and upon such terms as are just, permit

the party to serve a supplemental pleading setting forth

transactions or 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. A supplemental

pleading relates back to the date of the original pleading if it

arises out of the conduct, transaction, or occurrence set forth in

the original pleading.