Enacted effective October 1, 2011 · Last verified June 26, 2026
In one sentenceRule 13 distinguishes compulsory counterclaims — which arise from the same transaction and must be raised or lost — from permissive counterclaims and from crossclaims against co-parties.
(1)In General. A pleading must state as a counterclaim any claim that -- at the time of its service -- the pleader has against an opposing party if the claim:
(A)arises out of the transaction or occurrence that is the subject matter of the opposing party’s claim; and
(B)does not require adding another party over whom the court cannot acquire jurisdiction.
(2)Exceptions. The pleader need not state the claim if:
(A)when the action was commenced, the claim was the subject of another pending action; or
(B)the opposing party sued on its claim by attachment or other process that did not establish personal jurisdiction over the pleader on that claim, and the pleader does not assert any counterclaim under this rule.
(b)Permissive Counterclaims. A pleading may state as a counterclaim against an opposing party any claim that is not compulsory.
(c)Relief Sought in a Counterclaim. A counterclaim need not diminish or defeat the recovery sought by the opposing party. It may request relief that exceeds in amount or differs in kind from the relief sought by the opposing party.
(d)Counterclaim against the State. These rules do not expand the right to assert a counterclaim -- or to claim a credit -- against the State of Montana or a state officer or agency.
(e)Counterclaim Maturing or Acquired after Pleading. The court may permit a party to file a supplemental pleading asserting a counterclaim that matured or was acquired by the party after serving an earlier pleading.
(g)Crossclaim against a Coparty. A pleading may state as a crossclaim any claim by one party against a coparty if the claim arises out of the transaction or occurrence that is the subject matter of the original action or of a counterclaim, or if the claim relates to any property that is the subject matter of the original action. The crossclaim may include a claim that the coparty is or may be liable to the crossclaimant for all or part of a claim asserted in the action against the crossclaimant.
(h)Joining Additional Parties.Rules 19 and 20 govern the addition of a person as a party to a counterclaim or crossclaim.
(i)Separate Trials; Separate Judgments. If the court orders separate trials under Rule 42(b), it may enter judgment on a counterclaim or crossclaim under Rule 54(b) when it has jurisdiction to do so, even if the opposing party’s claims have been dismissed or otherwise resolved.
Plain-English Summary
When you are sued, Rule 13 governs the claims you can — and sometimes must — assert back.
A compulsory counterclaim is one you have against the opposing party that arises out of the same transaction or occurrence as their claim. You must plead it in the same case or you lose it, subject to narrow exceptions. Any other claim is a permissive counterclaim that you may raise but need not. A counterclaim can seek more, or different, relief than the opposing party sought.
A crossclaim is a claim against a co-party — someone on your own side of the “v.” — and is allowed only if it arises from the same transaction or relates to the property at issue. Rule 13 also addresses joining additional parties (through Rules 19 and 20), after-acquired counterclaims, and the limited rules for claims against the State.
Frequently Asked Questions
What is a compulsory counterclaim?
A claim you have against an opposing party that arises out of the same transaction or occurrence as their claim. You must assert it in the same action or you forfeit it.
What is the difference between a counterclaim and a crossclaim?
A counterclaim is asserted against an opposing party. A crossclaim is asserted against a co-party (someone on the same side), and only if it arises from the same transaction or relates to the property at issue.
Can my counterclaim seek more than the plaintiff is seeking?
Yes. A counterclaim may request relief that exceeds in amount or differs in kind from the relief the opposing party seeks.
Source & verification. Reproduced verbatim from the Montana Code Annotated as
published by the State Law Library of Montana and the Montana Legislature. This rule has not been amended since its adoption.
Adopted by the Supreme Court of Montana (AF 07-0157). Last verified June 26, 2026. ·
Official text
Also known as:counterclaimcrossclaimcompulsory counterclaimpermissive counterclaim