Operation Unfathomable (d20)
BEHOLD the Underworld in all its bewildering majesty as titanic Chaos Godlings and their unsavory cults make genocidal war upon each other!
SEIZE eldritch artifacts and treasures far above your lowly station!
THRILL as you throw the gauntlet of your life into the smug face of the unknowable and embark upon OPERATION UNFATHOMABLE!
OPERATION UNFATHOMABLE is a 108-page¸ internally-consistent¸ gonzo funhouse module for Swords & Wizardry that runs like a subterranean wilderness trek instead of a "down the 10 foot hall and kick in a door" affair. There are random elements aplenty to keep GMs guessing as well as players. No balanced encounters to be found here¸ but the clever setup allows low level characters to drop into the dungeon "deep end" and still have a chance of making it out alive-if they're smart and wary.