Demons and Devils is a 2001 role-playing game adventure published by Necromancer Games. Plot summary. "Demons and Devils" is an adventure in which three short dungeons adventures are compiled. Publication history. Shannon Appelcline noted that "Necromancer produced much more standard fare for the early d20 market - which is to say adventures. This started off with "The Crucible of Freya" (2000), the "Rappan Athak" mega-dungeon (2000) and "Demons and Devils" (2000)."