Mass. R. Dom. Rel. P. Rule 13
Counterclaim and Cross-Complaint
(a) Compulsory Counterclaims. A pleading shall state as a counterclaim any claim for relief the court has power to give 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 either require for its adjudication the presence of third parties over whom the court cannot acquire jurisdiction or constitute an action required by law to be brought in a county other than the county in which the court is sitting. 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 his 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. Identical to Mass.R.Civ.P. 13(b).
(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. Identical to Mass.R.Civ.P. 13(c).
(d) Counterclaim Against the Commonwealth. 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 Commonwealth of Massachusetts or a political subdivision thereof, or any of their officers and agencies. Identical to Mass.R.Civ.P. 13(d).
(e) Counterclaim Maturing or Acquired After Pleading. A claim which either matured or was acquired by the pleader after serving his pleading may, with the permission of the court, be presented as a counterclaim by supplemental pleading. Identical to Mass.R.Civ.P. 13(e).
(f) Omitted Counterclaim. When a pleader fails to set up a counterclaim through oversight, inadvertence, or excusable neglect, or when justice requires, he may by leave of court set up the counterclaim by amendment. Identical to Mass.R.Civ.P. 13(f).
(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. Identical to Mass.R.Civ.P. 13(g).
(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. Identical to Mass.R.Civ.P. 13(h).
(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. Identical to Mass.R.Civ.P. 13(i).
(j) Cross-Complaint. In a contested action for divorce if the defendant upon payment of the proper entry fee and at any time prior to the conclusion of the hearing shall cause to be entered his or her cross-complaint for divorce, the court shall allow the entry of said cross-complaint after giving of such notice or service to the new defendant as the court, in its discretion, shall order.