We already knew that a design document existed for a third (and unfortunately cancelled) Ultima Underworld title, but now the folks at Pix's ORIGIN Adventures have gotten their hands on a PDF containing the contents of the game's original story document, dated August 22nd, 1997. Apparently the game was going to split away from the Ultima world, which would have obviously meant that its working title was due for a change-up. Anyway, here's a transcribed sample from the document:
Around you are the corpses of others who have tried to escape...and failed. These corpses, scattered along the floors or leaning against the slimy stone walls, possess a few offensive and defensive weapons for the taking. Oh, and if you'd like to familiarize yourself with the awesomeness that is/was Ultima Underworld: The Stygian Abyss, Jay over at Rampant Games has a brief retrospective for you. Thanks, Ultima Aiera via RPG Codex.
The objects (weapons, spells, etc.) you find in gameplay vary dramatically depending on the Difficulty Level you selected, your preferred Mode of Play (Warrior, Wizard, etc.) and the number of Players in the game.
Alone in this eerie dungeon, you proceed through a series of tunnels, caverns and passages nothing too complex at this early stage of the game. You're not going to get hopelessly lost in here, but you better believe that you can be killed.
You'll encounter a rich world of sounds throughout Underworld 3. Monsters scream when attacking or dying, and generally provide a chilling variety of noises as you progress through a level.
Ambient sounds include dripping water, doors creaking, the distant groans and growls of creatures, etc.
The dark, forbidding environment sets the mood for the entire experience as you wend your way through torch-lit areas, alternately hunting down or running from monsters. These consist mostly of RATS, SLIMES, BEETLES and WORMS though a far cry from the relatively benign versions you may have encountered back on Earth.
You have two options for recovering Hit Points...
REST: walking very slowly without combat action. Your Hit Points rebuild slowly, yet steadily.
SLEEP: laying down and stopping completely, during which Hit Points rebuild much more quickly. However, sleeping does leave you vulnerable to attack or other disturbances.
In either case, Game Time always continues.
Soon you meet YERIK, a former mage who was cast into the prison and later escaped into this adjoining dungeon area. He's a gaunt, emaciated figure with deep-sunken eyes and pale skin. His hair is stringy and he's clad in rags.