Hecatomb

The third installment of the famed Heretic / Hexen series that was later abandoned by Raven Software after its acquisition by Activision and John Romero leaving id Software. A very few select ideas from Hecatomb made it's way into Raven's later titles (Hexen 2 and Heretic 2).

The player assumed a role of 3 different classes with 3 different types in each class. Similar to the Dungeons and Dragons Lawful/Neutral/Evil alignments each class had a good/bad side to it.

Fighter: Good = Paladin / Neutral = Warrior / Evil = Berserker
Mage: Good = Archmage / Neutral = Wizard / Evil = Necromancer
Thief: Good = Rouge / Neutral = Thief / Evil = Assassin

Depending on the players class/alignment and level of progress the game would randomly choose an automatic event to happen at certain points in levels.
The world design surrounding Hecatomb would be explored like one massive area divided into hubs (for it to run properly on systems). The player had to explore around the surrounding areas of a giant ages old castle, the various areas (such as swamps, caves, etc.) would naturally connect to central parts of the castle. After exploring all the areas the player would be given access to the deep regions inside the castle, where a dragon is guarding a powerful relic and treasure horde. After defeating the dragon and the player acquiring what they were after the area caves in and exposes and even older extensive underground network of catacombs -- at the end of which is a very old and evil Demilich that the player had to kill to escape. (source)

"Hecatomb was supposed to be the 3rd game, but I left id before fulfilling that goal." ~ John Romero