Conn. Practice Book § 10-10 (2026)

Sec. 10-10. Supplemental Pleadings; Counterclaims Supplemental pleadings showing matters arising since the original pleading may be filed in actions for equitable relief by either party. In any action for legal or equitable relief, any defendant may file counterclaims against any plaintiff and cross claims against any codefendant provided that each such counterclaim and cross claim arises out of the transaction or one of the transactions which is the subject of the plaintiff’s complaint; and if necessary, additional parties may be summoned in to answer any such counterclaim or cross claim. A defendant may also file a counterclaim or cross claim under this section against any other party to the action for the purpose of establishing that party’s liability to the defendant for all or part of the plaintiff’s claim against that defendant. (P.B. 1978-1997, Sec. 116.)