Adventures in Fantasy (1979)

From the box:

"ADVENTURES IN FANTASY is the next generation of FANTASY ROLE PLAYING GAMES. YOU are the Knight sent upon a Quest by the King to battle villains and creatures right out of Mythology. From Dwarves to Dragons your wits will be just as useful as your sword. This game comes complete with separate CHARTS, 20-Sided DIE, Sample Adventure and complete rules for starting on the road to high Adventure."

 From the web:

This boxed set of rules contains three full sized booklets:

58-page Book of Adventure (printed in blue ink) with the rules of the game and of character creation. This booklet also includes information for the gamemaster on creating and running adventures.

52-page Book of Faerry and Magic (printed in green ink) with magic spells and the races of Faerry.

52-page Book of Creatures and Treasure (printed in red ink) with monsters and treasure