Make the Most of Tomb of Annihilation with the Dungeon of Doom

Dwarven Forge provides free adventures for D&D 5E and Pathfinder. Let’s add Dungeon of Doom into Tomb of Annihilation!

What is Dungeon of Doom About?

Dungeon of Doom is a trap-filled dungeon and the first of several free adventures provided by Dwarven Forge, a manufacturer of amazing terrain for use with miniatures. Recently, I provided ideas on using the adventures with official 5E D&D adventures. On my Twitch and YouTube channels I showed off each of the adventures. And, huge thanks to Mike Shea (Sly Flourish) for mentioning my blog and YouTube channel on his show! Mike’s show is awesome, and his Patreon is fantastic!

Dwarven Forge terrain is amazing, but you can also run Dungeon of Doom (DoD) theater of the mind, on a battlemap, or with any terrain you have.

DoD is a labyrinthine deathtrap dungeon – but also more than that. While it appears that the wizard Zaltar has brought the heroes here to test them, in truth there is a far more vital reason. As the primary author, I worked with the Dwarven Forge team to ensure the dungeon had a strong story which unfolds as the party progresses. The dungeon steadily reveals its secrets and lore, and there are many roleplaying opportunities throughout.

For an overview of the encounter areas, see the final section of this blog and my video review. Here is the story overview from the adventure (spoilers):

Dungeon of Doom is a save-the-world tale set within the confines of a remote, danger-filled dungeon. The dungeon’s creator, Zaltar the Prince of Phantasm, challenges the party to face his deadliest creation – can they be the first to overcome the Dungeon of Doom? What party can resist facing a dungeon rumored to be equally full of deadly challenges and priceless treasures?

Once inside, the adventurers learn that things are a little more difficult and complicated than Zaltar let on. There’s no way to leave – the only means of escape is for the party to conquer the dungeon in its entirety, or die trying. Moreover, every minute the characters spend in the dungeon drains a little of their life-force until they perish – so they cannot afford any delays or even a rest! Worst of all, there’s a dark entity, a force of god-like potence, trapped somewhere within the complex and trying to break out. The deeper the party delves into the subterranean labyrinth, the greater the challenges they will face, and the more dire their situation will become.

There are, however, artifacts scattered throughout the dungeon – the 13 glyphstones of Eldrid – which will empower the adventurers. Each glyphstone also conveys part of the story of the dungeon’s creation so the players can eventually figure out Zaltar’s end game. Slowly they will come to the dreadful realization that they must destroy the entombed snake goddess Sysuul before she breaks free and annihilates all of Mythras.

DoD in Tomb of Annihilation (Spoilers)

One of Tomb of Annihilation’s many strengths is how easy it is to expand or contract the adventure. There are several ways you can add Dungeon of Doom. One or more of the encounters can form a small lost temple or ruin, filled with traps meant to test followers of the nine gods or even Ubtao.

My favorite, and what I did in my home campaign, is to insert the Dungeon of Doom into the Fane of the Night Serpent found in the lost city of Omu. Here are some reasons why this fits perfectly:

• In the Fane, two yuan-ti factions (Ras Nsi and Fenthaza) compete against one another to awaken Dendar. If Dendar awakens, he will destroy the world.
• Area 6 of the Fane is a sacrificial altar. Area 7 is a pool used to commune with Dendar. Area 9 is used for blood rituals and features a large blood pool.
• DoD has increasingly more snake imagery as the adventure progresses.
• DoD’s final threat is a part-snake demigoddess named Sysuul.
• In DoD, if Sysuul awakens she will destroy the land.
• In DoD, there are previous adventurers who have gone inside to test the dungeon. Most have perished, becoming spirits.
• The premise of DoD is that the wizard Zaltar has sealed away Sysuul, but needs life energy to keep her confined. He plays a dangerous game, bringing heroes to the dungeon. He hopes they will either die and fuel her prison or succeed and defeat her. There is the risk they will fail and allow her to escape.

We can place the Dungeon of Doom within the Fane. Locations 6, 7, or 9 all work well. I like the snake imagery in area 9, so I had the blood pool be the gateway. When a blood ritual is held in area 9, the pool allows access to area 1 of the Dungeon of Doom.

Zaltar and Sysuul were once the last of Ubtao’s guardians, and the Dungeon of Doom was once their training ground. Sysuul became corrupted by Dendar, empowered with a shard of his power. Just before she could release him, Zaltar discovered her treachery and sealed her in the very room that keeps Ubtao confined. Zaltar’s power continues to wane due to Ubtao’s departure. This weakens the altar holding Sysuul. If she escapes, she will release Dendar.

Both Ras Nsi and Fenthaza want to free Dendar and they know the method to do this must be within the dungeon. However, none who have entered the dungeon of doom have returned. The yuan-ti do not know what is inside, but they periodically send sacrifices, hoping they will either feed Dendar or manage to free him.

Zaltar has been playing a dangerous game – when the Yuan-ti send sacrifices, he allows them to explore the dungeon. If they die, their soul energy strengthens Sysuul’s prison, keeping her and Dendar at bay. If they should defeat Sysuul, Dendar will remain locked away for many years. But if the heroes release Sysuul and fail, the world will be destroyed. Lacking the power to fuel Sysuul’s prison himself, Zaltar must continue his risky game.

The encounters in Dungeon of Doom will largely work as written. Any NPCs found within were either explorers who became sacrifices of the yuan-ti, or apprentices to Sysuul or Zaltar. The soul energy described in the adventure is tied not only to Sysuul’s prison, but also to that of Dendar.

Ras Nsi and Fenthaza will consider it worth the risk to allow the PCs to enter the Dungeon of Doom. Either one may do so to prove to the other that they are in charge and taking bold action to free Dendar. Ras Nsi is especially likely to do this, as he needs the curse to end. He will grant the PCs anything they ask for if they agree to enter the Dungeon of Doom… including any puzzle cubes in his possession. Neither yuan-ti is entirely sure of what is taking place in the dungeon – no one who enters has returned. They therefore can’t tell the PCs what to do inside. They know it is a test of some sort, and thus wish for the PCs to enter and pass the test.

In my campaign, the PCs were captured. Ras Nsi used their capture as a way to show Fenthaza his power and then force them into the dungeon. Even if PCs are not captured, they can find the entrance to the dungeon or learn about it from any of the yuan-ti. Any of the main yuan-ti NPCs could have notes on them describing the rituals done to enter the dungeon of doom and wondering what may be inside.

Defeating Sysuul seals Dendar away for centuries. If a faction sent them, that faction loses power and the PCs can escape the Fane in the chaos.

Dungeon of Doom Encounters

Here is an overview of each of the 13 encounters. This will include spoilers! For greater depth, in this video I review the encounters.

1. Zaltar’s Gameroom
In this first antechamber, a trapped fallen body presents the heroes with their first test. Spirits appear, attempting to prevent the heroes from entering the main chamber. Within, Zaltar presents his challenge, promising great rewards if they prevail.

2. Arcane Alcove
PCs must brave a hallway trapped with scything blades to retrieve a key, then return to a talking door. Beyond is a spiked pit, easily jumped but for the invisible walls. The release for the walls of force is found on the skeleton within the pit. Treasure awaits, if they can solve the medusa pillar’s puzzle.

3. Lever Chamber
The circular chamber has four levels, leading to four small rooms. A puzzle hints at how to access the rune-warded trap doors in each room. Solve the puzzle to retrieve the three pieces of the Cryptic Key.

4. Deadly Corners
Orc adventurers made it this far before succumbing to the traps and spirits within. With their clues, can PCs unlock the doors and gain the treasure?

5. The Gauntlet
A trap-filled corridor challenging even the most cunning rogues. Pit traps, flame spouts, spiked traps, and more! Even those who stay behind aren’t safe. The encounter is meant to engage the whole party as they carefully plan each step to claim the glyphstone at the end.

6. Acid Bath
A bubbling floor of caustic acid, scything blades, snake pillars with eye-rays… and did we mention the two-headed caustic crocodile? There is more than meets the eye and great treasure as well.

7. Gorgon Tiers
A room with three tiers, and the metal gorgon at the top. How will you defeat such a terrible beast? And what of the other concealed threats? Metal, rock, and fire!

8. Puzzle Floors
A floating key (it’s in a transparent gelatinous cube, of course) leads to a puzzle floor and pillars containing clues. The ghostly visions are out of order. Determine the proper history and seize the treasure!

9. Eldritch Pools
Ensorcelled pools guarded by spirits teleports some heroes, but perhaps not all of the heroes, to face the even more potent magic of the spectral obelisk. Never split the party?

10. The Menagerie
A fearsome tiefling offers secrets in exchange for freedom. The other cages hold beasts and terrors. Many choices, but which are the deadly threats?

11. Doomroller’s Labyrinth
The massive boulder is composed of the skeletons of those who perished before. The doomroller chases the adventurers through a maze of traps as they desperately seek to gain the treasure and escape with their lives!

12. Dais of the Dead
Solve the riddle of the dead and contemplate the sacrifices of those who came before. Niches filled with bones hold secrets, and terrors. This room engages the party with difficult choices while revealing important lore. You can use it as a model for your own such encounters.

13. Lava Bridge
All the heroes have to do is ferry a fragile magic orb across a deadly span over molten lava. The ancient abyssal vermillion does make the task harder, and secret paths abound.

14. Khri Colony
Insectoid creatures have infiltrated the dungeon, building their maze-like hive around a treasure they stole… and which the heroes need. Disturbing their eggs evokes a moment out of my favorite horror film, Alien!

15. Shrine of Sysuul
Veiled by the dust of a shattered altar, in a place where darkness and light are keys, the dark wrath of a forbidden goddess awakens. The final challenge of the Dungeon of Doom!

You can find a walkthrough of these encounters on my YouTube channel. Have fun storming the Dungeon of Doom!