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  • Writer's pictureNikola Petrov

Dungeon23: The Perfect Game Design Excercise?

Here’s a crazy idea:

An epic-size but low-pressure year-long roleplaying jam might be the best game design exercise you’ll engage with this year.

What Is Dungeon23?

#Dungeon23 is a game jam of sorts. It’s an idea originated by Sean McCoy, designer of acclaimed indie horror RPG MOTHERSHIP.

The idea here is pretty simple: design a megadungeon that spans 12 levels deep and 365 rooms wide. Design one room every day for a year. Keep it all in a journal. That’s pretty much it!

In case you want to know a bit more, Ben Milton of the Questing Beast has a brilliant video going into more detail.

The initiative started on January 1st, so I’m taking the opportunity to talk about it a month later and encourage everyone to join–it’s definitely not too late and it’s much easier than you might think!

What System or Setting Is It For?

Whatever you want. Obviously, it could be D&D or another big dungeon crawler like Pathfinder, OSE, and so on, but who’s stopping you from setting it in space, in the Weird West, or in the basement below your house? It’s your dungeon! Personally, I’m going mostly systemless for now, focusing on puzzles and interesting environments and placing generic monsters such as “Goblins” or “A very powerful Lizard”. I can always stat these later or let whoever tries to run this as an actual game adapt the monsters to their system of choice.

For a year now, I’ve been drifting away from Dungeons & Dragons and leaning heavily on OSR, mostly MÖRK BORG, and one of the many beautiful things about these styles of games is that stats and game balance are of little importance.

Filling 365 rooms with interesting stuff is no easy feat and obviously, some of them might end up feeling disconnected, random, or not part of the same story. So here’s the kicker: that’s perfectly fine. If this ends up being a funhouse megadungeon, that would be a lot of fun. If it ends up being an epic movie-like campaign… let’s face it, the chances of this are slim. But you get the point–the idea here is to flex the creative muscles and develop a nice game-building habit with minimal but daily effort, rather than crafting the next best-seller on DriveThruRPG.

That being said, my dungeon has a loose concept to it.

Dungeon23 Concept
What does your megadungeon look like? (Credit:

So, What’s My Idea?

Ages ago, a kind and beloved ruler built the foundation of a mighty ziggurat. She dedicated the ground floor to her people and in a poetic turn of events, the architecture, art, and the very layout of the building became a living monument to her reign–an age of prosperity, justice, and virtue.

The ruler passed the beginning of this massive palace to her heir–an ambitious princeling who was meant to continue his parent’s work and build up from there. But jealousy and pride took deep root and corruption clawed its way inside the prince’s heart. The taller the ziggurat gets, the smaller the level is, so why should he be remembered as the lesser man? Ney, an even mightier level will be added to the building–dug below, instead of built above. Thus the first subterranean level was conceived. Ironically, it also reflected the rule of its builder–a place of darkness, danger, and peril.

For 10 generations corruption spread, twisting into pure evil. Every new hair will try to outdo their ancestors and dig ever deeper. As the pit grew deeper and darker, people grew desperate. This cycle of jealousy and pride was ultimately broken when a fabled hero took the head of the 11th heir and led the people back on the surface to start a new life. They moved far away and settled in a new land, away from corruption and decadence.

The Ziggurat of Damnation, as it is now known, turned into a ruin, infested only by beasts and death traps, but also holding untold treasures. While its ghastly remains lay abandoned, its legacy is not forgotten. Its 12 levels built in the 12 ages are still used as living history, a measurement of time, and a cautionary tale.

That’s right, my dungeon is a calendar! Each floor will represent one age in the history of this mythical civilization and its descent into evil and despair. The architecture and layout will provide hints about the ruler who built them and the monsters and traps will become deadlier and deadlier the deeper into this inverse pyramid you go.

Dungeon23 weekly promotps
Twitter is full of excellent resources, suggestions, and prompts!


The format has proven extremely popular. It enjoys promotion by prominent content creators, Discord servers, and other networks in the RPG space, as well as multiple bespoke communities formed and centered specifically around Dungeon23.

I am tempted to shower you with useful links to blogs, tools, assets, and books, but instead, I’ll pick just one in each category.

  • Best Community: r/Dungeon 23. The Subreddit dedicated to the megadungeon has 2.2k members as of the time of writing this blog post. It is very visual, with many people posting pictures of their journals. The craftsmanship and dedication of those folks are nothing short of inspiring!

  • Best resource: Maze Rats. This small zine is full of excellent random tables perfect for generating characters, magic items, spells, and potentially most importantly, dungeon rooms and environments. I’ve been a big fan of it for the longest time and I can’t recommend it enough!

  • Best Tool: Dungeon Alchemist. There are very many dungeon- and map-making programs out there, some of them free, some of their premium. And obviously, nothing beats a good old paper journal, especially one dedicated to Dungeon23. That being said, I figured I should share a potentially less-known piece of software available on Steam. The team is actively supporting it and it allows you to draw a detailed map or just press a button and let it generate and decorate stuff by itself. The maps have a top-down 3d, isometric, and flat look and there is an option to use maps designed with Dungeon Alchemist for commercial purposes! Nice!

Dungeon23 As An Excercise

To me, this is a perfect game design exercise.

First of all, it is very small and manageable, yet very effective at stimulating your brain. Taking as little as a few minutes per day to put a sentence or diagram on a page is enough to count, yet you can also spend an entire day thinking of an elaborate trap arrangement, a multi-phase boss battle, or a room that’s an in-doors marketplace complete with a dozen merchants to talk to and haggle with!

Second of all, your megadungeon’s rooms and levels can be as connected and story-rich as you want, or disjointed, gonzo, and random as it gets. And guess what: nobody says it can’t be a combination of those things!

Lastly, but certainly not by importance, it is a low-pressure jam! The police won’t come and arrest you because you had a bad day, felt uninspired, or simply were unable to make a room due to travel or an RPG session that took a bit longer than scheduled. Simply write “the room is empty” and boom, it counts! How cool is that?

Dungeon23 the room is empty
It's okay to skip a day!

Dungeon23 As A Finished Product?

As I mentioned already, this mega-jam has tons of highly active communities. Some of the best-known names in the RPG movement are publicly involved in Dungeon23 and frequently report their progress.

That means that we can look forward to seeing some impressive and professionally-crafted Dungeon23 materials coming out right about that time next year. Will yours be one of them? Shoot me an email and let me know, I’d be glad to buy it!

Legally speaking, the RPG world has never had so many amazing systems offering open and simple licenses to publish commercially. If you’re a player of a Paizo game, a Free League game, MOTHERSHIP, Troika!, and even the upcoming project Black Flag and MCDM’s tactical system, it’s never been easier to convert and publish a cool thing and have a welcoming community play and support it! If publishing is not your primary goal (and it really shouldn’t be!) you can play your dungeon with your own groups. You can explore it as it is being created, run a massive campaign inside it next year when it’s done, or better yet - collaborate and create, amend, and extend it as you play!

At the very least, even if you don’t end up publishing or even playing your Dungeon23, you’ll be left with a great souvenir and your own treasure trove of dungeon room ideas and lessons learned about game design. And at the end of the day, that’s all that counts.

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Nadj Affari
Nadj Affari
Feb 24, 2023


Here's the setting I've been working on for the Dungeon23! It might serve as an inspiration or spark some discussion, or neither. But sharing is caring, as the saying goes. So here's me caring.


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