Rule 15.Amended and supplemental pleadings

Ch. III: Pleadings and Motions · Last amended 1996 · Current through June 1, 2026 · Last verified September 9, 2026

In one sentenceRule 15 allows one amendment as of course before a responsive pleading, leave freely given afterwards, and relation back to the original filing where the amendment grows out of the same conduct.

Full Text of Rule 15

Text sizeJump to: (a) (b) (c) (d)

(a) Amendments. A party may amend the party's 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 required or permitted and the action has not been placed upon the trial calendar, that party may so amend it at any time within 20 days after it is served. Otherwise a party may amend the party's pleading only by leave of Court or by written consent of the adverse party; and leave shall be freely given when justice so requires. A party shall plead in response to an amended pleading within the time remaining for response to the original pleading or within 10 days after service of the amended pleading, whichever period may be longer, unless the Court otherwise orders.

(aa) Form of Amendments. A party serving an amended pleading shall indicate plainly in the amended pleading in what respect the amendment differs from the pleading which it amends.

(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. Such amendment of the pleadings as may be necessary to cause them 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, 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 such evidence would prejudice the party in maintaining the action or defense upon the merits. The Court may grant a continuance to enable the objecting party to meet such evidence.

(1) relation back is permitted by the laws that provide 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 the foregoing provisions of subdivision (2) of this paragraph are satisfied and, within the period provided by law for commencing the action against the party, the party to be brought in by amendment (A) has received such notice of the institution of the action that the party 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 the party.

(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. If the Court deems it advisable that the adverse party plead thereto, it shall so order, specifying the time therefor.

End

Amendment History

Delaware prints each rule’s amendment history as a single “Credits” line naming every order that adopted or amended it. It is reproduced verbatim below.

[Amended effective September 3, 1996.]

Plain-English Summary

As of course, once. A party may amend once without permission at any time before a responsive pleading is served, or, where no responsive pleading is required and the action has not been reached for trial, within the period the rule allows. After that, by leave of court or written consent of the other side.

Show the change. A party serving an amended pleading must indicate plainly how the amendment differs from what it replaces. A small requirement that saves everyone from reading two documents side by side.

Conforming to the evidence. Where issues not raised by the pleadings are tried by express or implied consent, they are treated in every respect as if they had been pleaded, and the pleadings may be amended to say so — even after judgment.

Relation back. An amendment relates back to the date of the original pleading in three situations: where the law supplying the limitation period permits it; where the claim or defence arose out of the conduct, transaction or occurrence set out or attempted in the original pleading; or where the amendment changes the party sued and the same-transaction test is met, provided the new party had notice within the period allowed for commencing the action. Relation back is what keeps a limitation period from turning a drafting slip into a lost case.

Supplemental pleadings. On motion, reasonable notice and just terms, the court may allow a party to plead transactions, occurrences or events that have happened since the pleading being supplemented.

Frequently Asked Questions

Can I amend my petition in the Delaware Family Court?

Once as a matter of course before a responsive pleading is served; after that by leave of court or the written consent of the other party.

Do I have to show what I changed?

Yes. A party serving an amended pleading must indicate plainly in it how the amendment differs from the pleading it amends.

Will my amendment count as filed on the original date?

It relates back where the applicable limitations law permits it, or where the new claim or defence arose out of the conduct, transaction or occurrence set out in the original pleading — and, for a change of party, where that party had notice within the period allowed for commencing the action.

What about things that happened after I filed?

On motion, and upon reasonable notice and just terms, the court may permit a supplemental pleading setting out transactions, occurrences or events since the pleading it supplements.

Source & verification. The rule text and amendment history are reproduced verbatim from the Delaware Family Court Rules of Civil Procedure (Fam. Ct. Civ. R. 15), and every rule has been checked word for word against the Delaware Family Court’s own published edition of these rules. Current through June 1, 2026. The plain-English summary is original and written by us. Last verified September 9, 2026. · Official source

Also known as: amend petition Delaware Family Courtrelation back Delawaresupplemental pleading DelawareFam. Ct. Civ. R. 15