The making of a mega-dungeon

Part 1 of my OSR dungeon-making process.

The indefatigably imaginative

Thog's Table

has assembled dozens of creative artists and writers to make a sprawling OD&D mega-dungeon right here on Substack.

And Thog was gracious enough to assign me with level 6: The Crawling City of Endless Night…what a title.

In the spirit of building this community, I want to share my process for making an OSR dungeon — all the art, writing, and mechanics I use to bring these beasts to the table.

I start with a map

I imagine most fantasy nerds are drawn to maps. For me, that’s where it starts. I like to draw my own — it helps me understand the space better and plan where I want the players to go first, second, and last.

I draw my dungeons as iso(metric) maps. This literally adds another dimension to the more conventional top-down map for me to detail with carvings, hidden doors, and tunnels.

First, I sketch the chambers and connections with a non-photo blue pencil. Then, I ink in the details using brush pens. This might look familiar to folks who read comics — it’s the same concept.

Inking the northern corner of The City

Fill the emptiness with mystery

I’m of the mind that an empty chamber needs to be filled with mystery or cut from the dungeon. There’s nothing wrong with a dark echoing chamber — that’s evocative — but nature abhors a vacuum and players can’t interact with undeveloped details. If it has to be empty, it should at least smell like a rotting carcass or pulse with infrasound.

I give each chamber a key feature by rolling a d100 on the 3.5 DMG major dungeon features tables (Table 3-11). It’s not OD&D, and there are others out there, of course, but this one lives rent-free in my heart.

Table 3—11 from the 3.5 DMG

Mind-mapping the dungeon map

Drawing in the key features helps me mind-map the dungeon. This isn’t stocking the dungeon — that’s later. This step is for thinking deeply about each space and how it fits within the larger context and ecology. Why is this coffin here? Where is all this ooze coming from? Who’s using this kitchen and what the hell are they cooking?

These are questions my players might ask, and, while they may not find the answer, it should be discoverable. If they don’t find it, some C.H.U.D. might.

Once I’ve finished inking my map, I scan the page into InDesign to bleed off the blue lines and add numbers for the key.

The finished map ends up looking like this:

The finished map

With my map finished, I’m already primed to brainstorm what actually lives (and hunts) down here in The Crawling City of Endless Night. Besides the C.H.U.Ds, of course.

More to come on this behemoth.

Special thanks to

Thog's Table

—Odinson