Fighting Fantasy is the title given to a series of interactive novels also known as Gamebooks that were developed by Steve Jackson and Ian Livingstone (Founders of Games Workshop & veterans and living legends of the gaming industry).
They had a huge following during the 1980s and 1990s.
The FF books were ground-breaking in their heyday as they provided the reader with the chance to enjoy a good fantasy story as well as, for the first time, allowing the reader to guide the direction of the story to one of numerous end variations.