The Fool's Errand
The Fool's Errand is a 1987 meta-puzzle developed by Cliff Johnson and published by Miles Computing. It was originally for the Macintosh, but was later ported to MS-DOS, Amiga, and Atari ST systems.
(NOTE: these ports, despite adding color, are generally considered to be inferior to the original Mac OS version because they are buggier and lower resolution)
The plot follows a fool who journeys through a fantasy realm based on the cards of the Rider-Waite tarot deck, in order to find the 14 "treasures of the world" and gain wisdom. The game is structured as a five-part storybook. Each of these five parts contains a large number of different chapters, each based on a tarot card from either the Major or Minor Arcana.
However, only a couple of chapters are avaliable at the start of the game, and they are scattered about the story rather than a clean, consecutive 1-2-3-etc arrangement. To access more chapters, you must find a chapter which has a puzzle (called an enchantment) associated with it, which you can then solve to unlock another chapter in another part of the story which the solution to the puzzle was taken from.
At first, the goal is to unlock every chapter because the Sun's map is a sort of jigsaw puzzle with every piece representing a chapter you've unlocked. Then, once the map is completed, the pictures on it become clickable clues/processes used to decipher the true final puzzle, which will require you to read the fully-unlocked story front-to-back in order to succeed...
Links
Bonus resource: I've created a text file adaptation of the game's story, which you can read here. (spoilers!)
Cliff Johnson - Where you can get The Fool's Errand for free, and find lots of information about it, along with lots of other interesting stuff, like the Original Manual, and the Hints and Answers Book. But most of all, you NEED to look at the beautiful artwork for the !unreleased Mac II version of The Fool's Errand, all with a higher-resolution and richer detail than the original version of the game.
Digital Antiquarian: Cliff Johnson’s Fool’s Errand - Interesting article about the game's development.
Arcade Idea: The Fool’s Errand