N.Y. Civil Practice Law & Rules § 3019: Counterclaims and cross-claims

§ 3019. Counterclaims and cross-claims. (a) Subject of counterclaims.

A counterclaim may be any cause of action in favor of one or more

defendants or a person whom a defendant represents against one or more

plaintiffs, a person whom a plaintiff represents or a plaintiff and

other persons alleged to be liable.

(b) Subject of cross-claims. A cross-claim may be any cause of action

in favor of one or more defendants or a person whom a defendant

represents against one or more defendants, a person whom a defendant

represents or a defendant and other persons alleged to be liable. A

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.

(c) Counterclaim against trustee or nominal plaintiff. In an action

brought by a trustee or in the name of a plaintiff who has no actual

interest in the contract upon which it is founded, a claim against the

plaintiff shall not be allowed as a counterclaim, but a claim existing

against the person beneficially interested shall be allowed as a

counterclaim to the extent of the plaintiff's claim, if it might have

been so allowed in an action brought by the person beneficially

interested.

(d) Cause of action in counterclaim or cross-claim deemed in

complaint. A cause of action contained in a counterclaim or a

cross-claim shall be treated, as far as practicable, as if it were

contained in a complaint, except that separate process, trial or

judgment may not be had unless the court so orders. Where a person not a

party is alleged to be liable a summons and answer containing the

counterclaim or cross-claim shall be filed, whereupon he or she shall

become a defendant. Service upon such a defendant shall be by serving a

summons and answer containing the counterclaim or cross-claim. Such

defendant shall serve a reply or answer as if he or she were originally

a party.