Counterclaim and cross-complaint

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.