III. PLEADINGS AND MOTIONS > Rule 13.
Rule 13. Counterclaim and Cross-Claim
(a) Compulsory Counterclaims.
A pleading shall state as a counterclaim
any claim which at the time of serving the pleading the
pleader has against any opposing party, if it arises out
of the transaction or occurrence that is the subject matter
of the opposing party's claim and does not require for its
adjudication the presence of third parties of whom the court
cannot acquire jurisdiction. But the pleader need not state
the claim if (1) at the time the action was commenced the
claim was the subject of another pending action, or (2)
the opposing party brought suit upon the claim by attachment
or other process by which the court did not acquire jurisdiction
to render a personal judgment on that claim, and the pleader
is not stating any counterclaim under this Rule 13.
(b) Permissive Counterclaims.
A pleading may state as a counterclaim
any claim against an opposing party not arising out of the
transaction or occurrence that is the subject matter of
the opposing party's claim.
(c) Counterclaim Exceeding Opposing
Claim.
A counterclaim may or may not diminish
or defeat the recovery sought by the opposing party. It
may claim relief exceeding in amount or different in kind
from that sought in the pleading of the opposing party.
(d) Counterclaim Against the United
States.
These rules shall not be construed
to enlarge beyond the limits now fixed by law the right
to assert counterclaims or to claim credits against the
United States or an officer or agency thereof.
(e) Counterclaim Maturing or Acquired
After Pleading.
A claim which either matured or was
acquired by the pleader after serving a pleading may, with
the permission of the court, be presented as a counterclaim
by supplemental pleading.
(f) Omitted Counterclaim.
When a pleader fails to set up a
counterclaim through oversight, inadvertence, or excusable
neglect, or when justice requires, the pleader may by leave
of court set up the counterclaim by amendment.
(g) Cross-Claim Against Co-Party.
A pleading may state as a cross-claim
any claim by one party against a co-party arising out of
the transaction or occurrence that is the subject matter
either of the original action or of a counterclaim therein
or relating to any property that is the subject matter of
the original action. Such cross-claim may include a claim
that the party against whom it is asserted is or may be
liable to the cross-claimant for all or part of a claim
asserted in the action against the cross-claimant.
(h) Joinder of Additional Parties.
Persons other than those made parties
to the original action may be made parties to a counterclaim
or cross-claim in accordance with the provisions of Rules 19 and 20.
(i) Separate Trials; Separate Judgments.
If the court orders separate trials
as provided in Rule 42(b), judgment on a counterclaim or
cross-claim may be rendered in accordance with the terms
of Rule 54(b) when the court has jurisdiction so to do,
even if the claims of the opposing party have been dismissed
or otherwise disposed of.