Fighting Fantasy:The Warlock of Firetop Mountain by Ian Livingstone
PART STORY, PART GAME - PURE ADVENTURE! Are YOU brave enough to take on the monsters and magic of Firetop Mountain...? The powerful warlock Zagor must be slain - but first you'll need to make it through the caverns of his mountain stronghold. Many adventurers before you have taken a wrong turn in the maze and perished at the hands and claws of the Warlock's gruesome servants... step up, hero, it's time to fight!