Mass. Trial. Ct. R. 5
Counterclaims shall be permitted in accordance with the provisions of G.L. c. 239, §8A. Counterclaims shall be set forth in the defendant's answer and shall be expressly designated as counterclaims. The right to counterclaim shall be deemed to be waived as to the pending action if such a claim is not filed with the answer pursuant to Rule 3, unless the court shall otherwise order on motion for cause shown. Counter-claims shall not be considered compulsory; that is, they shall not be considered waived for the purpose of a separate civil action or actions if not asserted in a summary process action. No responsive pleading to a counterclaim is necessary.
Mass. Trial. Ct. R. 5
Commentary
This rule recognizes the statutory right of summary process defendants to assert counterclaims. Counterclaims must be asserted with the defendant's answer. A plaintiff against whom a counterclaim is asserted is not required to answer; but an answer to a counterclaim may be filed prior to or at the time of the trial. The court may, of course, in its discretion grant a motion for a continuance in order to grant a party time to prepare a defense to a counterclaim. Because counterclaims are not compulsory, the court retains discretion to sever a counterclaim which cannot appropriately be heard as part of the summary process action. It would, however, appear to be contrary to the law to sever a counterclaim which is being relied upon as a defense under G.L. c. 239, §8A.
It should be noted that the counterclaim provisions of G.L. c. 239, §8A apply to premises "rented or leased for dwelling purposes".