From publisher blurb: The legendary megadungeon is here at last for Fifth Edition! More than thirteen levels and over 1,500 keyed encounters of perils, monsters, traps, and treasure to bedevil your players. Find levels of warring humanoids, the deadly Arena, ancient artifacts, lost temples, portals to other worlds, and the ultimate secret of the dungeons... the Mad Archmage himself. Originally released as a free electronic book in serial format, the Castle of the Mad Archmage has been completely revised, expanded, and updated. It is a complete adventuring environment, from the surface ruins to the deepest caves and caverns. You and your players could literally spend years exploring the dungeons beneath the Castle and still not discover everything. It can accomodate characters from first to fifteenth experience level and beyond.