No reply shall be necessary on the part of the plaintiff, except when the defendant in the defendant's answer claims a lien or encumbrance upon the property which, prior to the commencement of the action, was barred by the statutes of limitation, or which shall have been discharged in bankruptcy, or which constitutes only a cloud, the plaintiff may reply setting up such defense and availing plaintiff of the benefit thereof, and in all cases in which the plaintiff has made permanent improvements on the property in good faith, while in possession under color of title, the plaintiff may recover the reasonable value thereof as against the defendant recovering the property when the reply shall allege the facts, stating particularly the value of the improvements and the value of the property, and shall demand appropriate relief. The reply shall be served on such defendant and filed with the clerk within twenty days after the service of the defendant's answer.
N.D.C.C. § 32-17-09