Mega Dungeon 2026

It has been some time since I entertained the idea of creating some kind of mega-dungeon for a TTRPG. I’ve played plenty of games in the past and I was sometimes a Dungeon Master as well. It was not a rare occurrence that I would grab published one-shots or campaigns from an editor, and play them at the table. They make for great stories and give you a lot of material to work with. However, even though you can make it your own through the way you are mastering, it doesn’t scratch enough the worldbuilding itch that I get. And that’s okay! Yet it takes time to create a world, to make it interesting, alive even. The land needs care, attention, and love. Like a plant, it starts from small watered seeds in fertile soil, and needs to grow before giving any flowers or fruits.

I stumbled, a couple of years ago, on a project by Sean McCoy called #Dungeon23. Each day, he creates a new room and a month represents a level, ending up with 12 levels and 365 rooms on the 31th of December. It also started a subreddit: r/Dungeon23. Three years later, creators keep building new rooms for their dungeons and share them on the internet.

In the same vein, there’s a challenge called “The Gygax 75 Challenge” in reference to Gary Gigax, one of the co-creator of Dungeons & Dragons. It goes way deeper than simply rooms in a dungeon. It’s about creating a brand new campaign. Quite a feat to achieve, isn’t it? The author, Ray Otus, split the building of a campaign into different steps, going from the ideation phase to an actual playable setting. All of it in the course of 6 weeks. I could no longer find the original material, however someone tried his hands on it and wrote about his experience: Frank Mitchell - The Gygax 75 Challenge Part 1: Concept.

It got me thinking: would it be great to have, at the end of the year, a mega dungeon? Hell yes! Yet, I’m going in a slightly different version of the Dungeon23 challenge. Instead of taking the word dungeon in the literal sense as in a structure of multiple rooms connected with each other and holding creatures, puzzles and loot, I went with another approach. Let’s create a region instead, uncharted territories for the players to explore, lands with countless possibilities. The inspiration came from two things:

  • The West Marches, a setting with a persistent world shared between multiple groups of players
  • The game Forbidden Lands which invites the players to explore a cursed land using a hex based map without following a linear campaign. It gives a great entry point into the OSR world.

General Guidelines

  • The map starts with a single hexagon
  • One hex represents a quarter day’s worth of walking; the amount of time increases when the terrain is rough
  • Each day, a new hexagon is placed beside an existing one
  • The description can be as little as a title, and as big as a full scenario’s chapter
  • Find ways to discover new avenues, try different mechanics, and ways to tell stories
  • Have fun

Tools

Pen and paper! There’s no need to go crazy with tools. Notebooks are great at being carried, whenever there’s a downtime, there’s an opportunity to write about a new part of the region. Perhaps, if I want to be a bit more fancy, I’ll dust off my drawing tablet and illustrate the tiles. I would love a map I could use as a wallpaper. Or better yet, use it as an actual setting in a TTRPG game!

Speaking of game, I’m not sure if I’ll use existing systems yet. I want to make the region not bound to a set of rules nor mechanics. A D&D and a Torchbearer DM may use the map without issues.

The World

It starts with an empty tile

Without further a due, welcome to The Cauldron