As an ancient dungeon located in the magical realm of Thay, the Doomvault was defended by numerous powerful Red Wizards, their golem servants, and a multitude of varied monsters, bound outsiders, and raised undead, as well as magical traps and natural hazards.
The Red Wizard Kazit Gul spent the vast majority of his lifespan studying the most famous and deadly dungeons in Faerûn. Towards the end of his life, he began constructing a vast labyrinth and successfully pursued lichdom in order to finish his work. The purpose of the dungeon was to lure adventurers inside where Kazit Gul could then devour their souls to empower his phylactery.
The Doomvault passed into legend as Thay became a less welcoming place to foreigners but Szass Tam rediscovered and repurposed it to his own ends.
When Tam learned of the Sundering, he had his agents capture several Chosen for experimentation. They were brought to Doomvault with an eye toward using their divine power to aid Tam's goal of apotheosis.
- Kazit Gul: The dungeon's original creator.
- Tarul Var: A trusted lich servant of Szass Tam.
- Syranna: The overseer of the Doomvault's gatehouse and a leader of the Thayan Resurrection.
- Issem: A vampire, cursed to be bound to Doomvault and the will of the Red Wizards.
- Pencheska: A succubus servant of Tarul Var.
- Lahnis: A Red Wizard in charge of combat training.
- Phaia: A devoted servant of Szass Tam.
- Thaxalia: A beholder, crippled by the Red Wizards and cursed to be unable to escape.
- Sarkalla: An insane Red Wizard obsessed with granting intelligence to oozes.
- The Ooze Master: An experiment to fuse an ooze with a human, resulting in a new type of lich.
- Lumalia: An astral deva servant of Mystra.