(a) Counterclaims. A pleading may state as a counterclaim any claim which at the time of serving the pleading, the pleader has against an opposing party.
(b) Failure to Include Counterclaim; Effect in Subsequent Action. A party who does not assert a counterclaim that arises out of the transaction or occurrence that is the subject matter of an opposing party's claim cannot recover costs against that party in any subsequent action thereon.
(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 State and Political Subdivisions. 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 State of Nebraska, an officer or agency of the State, or a political subdivision of the State.
(e) Counterclaim Maturing or Acquired After Pleading. A claim which either matured or was acquired by the pleader after filing 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. [Reserved]
(i) Separate Trials; Separate Judgments. [Reserved]