No Prep Dungeon: Undead Plague

This adventure can be can be easily customized to a party of any size or level, or run as a level 3 adventure for 5 players. It can work as a small side adventure in an existing campaign, as a standalone one-shot, or the start of a new adventure. Use the links to the tools in their relevant section to customize the adventure to your party.


  • The players learn that rat catchers are going missing under the city and a plague is spreading in their absence.
  • Most of the populace is sick, a DC 10 Medicine check can identify it as a contagious plague spread by rats.
  • If the PCs go searching for rats, they'll find that most of them seem to be coming from under the city.

Underneath the city is a large crypt, once the site of an ancient battle. Thick, icy fog swirls in the entryway. The room has rough-hewn walls and a floor made of dampened clay and soil. Far off in the dark is the sound of rattling bones and wailing groans. Life-sized statues of cavaliers line the crypt on each side, their eyes seeming to follow you.

The crypt under the city has become an area of deadlands that's growing every day, and will threaten the city and countryside if not stopped.

A tall, domed ceiling caps the large octagonal room before you. The ground is choked with ash, while webs hang from the curved ceiling like drapes. Dim, colored light filters through tall and broken windows of stained glass, slightly illuminating the area. On the far end of the room is a closed stone door, with writing etched upon the wall beside it.

In one of the key rooms (red, blue, or green) the party enters a room with a stone wall and a locked door. The wall has a riddle engraved in it: 'The key is found within you head, use the key to paint me red. Be aware of what you spurn, for what you give shall be returned.'

  • The party must use blood and smear it on the wall(where they get it from is up to them), and a duplicate of what the blood came from emerges out of the wall. The party must fight and defeat the duplicate to unlock the door. You could also allow them to paint a key onto the door.

Cobwebs span between the columns that hold the high ceiling of this dusty tomb. Benches coated with decades of dust lie around the floor in chaotic disarray. It's dimly lit with flickering torches in metal sconces, casting long shadows across the face of a cloaked undead that floats just above the ground. Its voice is a dark and crackling whisper that sends shivers down your spine, "you are too late. The deadlands are seeded across the other cities, and will soon choke the life from this continent."

In the final room is an undead general. It is just one member in a secret alliance of undead, each spreading deadlands in cities around the globe.

  • The boss is blind (but has echolocation/tremorsense) and has resistance to all damage, but vulnerability when in natural light. The PCs need to lead it into beams of light around the arena. They get a full round of damage before the boss destroys the light source.

Undead General Battlemap

You can use your own battlemap, or use this one. The circles of brightness are zones of natural light where the boss is vulnerable.

With a piercing wail, the cloaked undead crumbles to the ground as a pile of dust under its billowing cloak.

  • With the general destroyed, the deadlands slowly begins to shrink over the course of a couple days until it's gone.

There are still deadlands spreading in other cities, and the players must decide what to do about it. This could lead to another series of quests or campaign to stop the undead plot.

Need more help with your campaign? Check out all the other tools, generators, and articles: kassoon.com/dnd/

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