Defenses to be specially pleaded. Any defense that a contract or writing sued on is void

or voidable, or was delivered in escrow, or which alleges any matter in justification, excuse, release or discharge, or which admits the facts of the adverse pleading but seeks to avoid their legal effect, must be specially pleaded. [Report October 31, 1997, effective January 24, 1998; November 9, 2001, effective February 15, 2002]