509.420. What a pleading shall state as a counterclaim. - Missouri Statutes

What a pleading shall state as a counterclaim.

509.420. A pleading shall state as a counterclaim any claim,not the subject of a pending action, which at the time of filingthe pleading the pleader has against any opposing party, if itarises out of the transaction or occurrences that is the subjectmatter of the opposing party's claim and does not require for itsadjudication the presence of third parties of whom the courtcannot acquire jurisdiction.

(L. 1943 p. 353 § 73)