In the Labyrinth (Revised)

From publisher blurb: Monsters and Treasure! Old-school dungeon-crawling is at its best in The Fantasy Trip. This book covers roleplaying, character creation and experience, and advanced magic and combat rules for players who already have Melee and Wizard. First released in 1980 and unavailable for decades, In the Labyrinth is back in a new, expanded, and improved edition for daring dungeon-delvers!