Madness and the Minotaur

A bold adventurer descends into the enormous labyrinth of the Cretan King Minos at Knossos, hoping to part seven mythical monsters (including the terrifying, titular, Minotaur) from sixteen treasures and escape with his life, helped only by a handful of arcane spells acquired while navigating dead ends and the enigmatic ramblings of an inspired Oracle wandering the maze.

It's not entirely fair to blame the period hardware limitations for this game's poorly-aged VERB NOUN text parser, as Infocom first launched home versions of Zork I a year earlier, but at the time its grammar was still industry-standard par for the course. What made this title stand out is also what kept its adherents on their toes (... for decades) -- inconstant internal rules and conditions that changed every time the game was played.

Much like the color of potions in Nethack shuffling their associations with spell effects between games, this game not only jumbles the relation between spell names and their effects, but also the conditions that must be met in order to learn them! Similarly unpredictable are the locations and vulnerabilities of monsters and treasures. Add to that a huge (four floors of 64 rooms each) maze full of one-way passages, bogus "dummy" treasures, realtime monster movement, unreliable and abstruse room connections and you end up with a devious dungeon indeed.