RCW 7.28.120: Pleadings—Superior title prevails.

The plaintiff in such action shall set forth in his or her complaint the nature of his or her estate, claim, or title to the property, and the defendant may set up a legal or equitable defense to plaintiff's claims; and the superior title, whether legal or equitable, shall prevail. The property shall be described with such certainty as to enable the possession thereof to be delivered if a recovery be had.