A counter-claim is a claim for relief asserted against an opposing party after an original claim has been made; such as, a defendant’s claim in opposition to or as a setoff against the plaintiff’s claim.  A counterclaim arises when the defendant’s response includes a claim against the plaintiff.  A counterclaim may come from the same circumstances as the plaintiff’s claim or from a different set of facts.  It is also called a counteraction; countersuit; cross-demand or cross-claim

A counterclaim must contain facts sufficient to support the granting of relief to the defendant if the facts are proved to be true.  These facts may either refer to the same event that gave rise to the plaintiff’s Cause of Action or they may refer to an entirely different claim that the defendant has against the plaintiff. Where there is more than one party on a side, a counterclaim may be made by any defendant against any plaintiff or plaintiffs.

A defendant is usually required to make a counterclaim in an answer if the counterclaim arises from the same transaction or occurrence on which the plaintiff is suing.  This is called a compulsory counterclaim; because the claim must be made in response to the plaintiff’s complaint and cannot be made later or in a separate lawsuit.  There are permissive counterclaims that may be made in the defendant’s answer at a later time.