In this episode I interview Che “Peter” Webster, a public school teacher in England, who’s DMing his school gaming group through The Caverns of Thracia using B/X Essentials.

Show Notes

Che’s blog, Ubiquitous Rat

Che’s MeWe profile

Che’s Twitter profile

The Terror of Ettinmarsh (Adventure)

Moonspike Tower (Adventure)

Classic Fantasy RPG

B/X Essentials by Gavin Norman

Listener Call-In Podcasts

DM Dad

Gothridge Manor



In this episode I’ll discuss one of the first published megadungeons, The Caverns of Thracia, and run it through my Megadungeon Purity Test. I also respond to some call-ins.

Show Notes

Judd’s gaming podcast Dreaming About Dragons

Colin Green’s gaming podcast Spikepit

PDF of the original release of The Caverns of Thracia on DriveThruRPG (The cost to fun ratio is in your favor!)


Advice: Print only what you need at the table and highlight the most important items.

Caverns of Thracia – Megadungeon Purity Test

Category #1: How big is it?

  Score: 2 points

Category #2: Is it set in a confined space?

  Score: 5 points

Category #3: Is it a Mythic Underworld?

  Score: 3 points.

Category #4: Does it get more dangerous the further down you explore?

  Score: 2 points.

Category #5: Are there multiple options for exploration?

  Score: 4 points.

Category #6: Is the danger omnipresent?

  Score: 4 points awarded.

Category #7: Could this be the focus of a campaign?

  Score: 1 point

Category #8: Is this an active or static dungeon?

  Score: 2 points

Total score: 23 points.

The question “What is a megadungeon?” was asked in Episode 1, and I shared some features that I think are indicative of the classic megadungeon. But even with that definition in hand, some of you might be wondering how does one megadungeon compare to another? Where do we draw the line? As a fun experiment, I propose the Megadungeon Purity Test. In future episodes I will take an in-depth look at published megadungeons, and with this tool I will attempt to rank them. There are 8 categories and each aligns with a feature discussed in Episode 1. A megadungeon in question can earn from 0 to 5 points per category.
  1. How big is it? – The most often discussed feature of a megadungeon is it’s shear size. I will consider page count, numbered encounters, dungeon levels, and how much experience the dungeon can provide when awarding points in this category.
  2. Is it a confined space? – It’s called a dungeon for a reason. This is not a campaign setting or a wilderness hexcrawl.
  3. Is it a Mythic Underworld? – Does the dungeon adhere to the Mythic Underworld concept? Are characters leaving the natural world and traveling into the supernatural? Are the rules of the dungeon different from those in the natural world?
  4. Does it get more dangerous the further down you explore? – Whether a vertical or horizontal dungeon, the further from the entrance(s) you go, the greater the challenges and risks.
  5. Are there multiple avenues for exploration? – Does this dungeon offer freedom to move from level to level and explore as desired rather than follow a set path? How numerous and varied are the connections between levels?
  6. Is the danger omnipresent? – How pervasive is the danger? Are the characters forced to trek back through the dungeon to resupply and rest?
  7. Is this dungeon the focus of a campaign? – Can this dungeon be the focus of an entire campaign? How much experience can be gained through exploration?
  8. Is the dungeon active or static? – Do traps reset, will monsters repopulate cleared areas, or can the dungeon change physically over time? Will  factions fight the characters and each other, gaining and losing territory?
For example, in Episode 1, I mentioned that The Maze of the Blue Medusa was less concerned with increasing difficulty as you descend, whereas Rappan Athuk is designed with that in mind. Perhaps MotBM would get 1 point for that category, and RA would get 5. The original Caverns of Thracia would score fewer points in the size category than Castle Whiterock. I think we’ll find that there is no perfect megadungeon, and some will pull more points than others in different categories. Let me know what you think, and I’ll put this intro practice in the future episodes. -Carl

The Megadungeon is a twice-monthly podcast about megadungeon adventures for fantasy and sci-fi role-playing games. I talk about the history, evolution, and design of various megadungeons, as well as interview authors, artists, and other who helped with the production of a published megadungeon.

The Minidungeon is a weekly unscripted podcast in which I talk about gaming in general. Topics vary, but the trials and tribulations of writing my own adventures is certainly one of them. 

I got my start in podcasting way back in 2008 when I hosted the Flagons & Dragons podcast, which was nominated for an ENnie award in 2009. These were the early days of podcasting and we had no strict format. Some weeks it was actual play, others it was commentary and advice, and towards the end of its 2-year run the rest of the hosts lost interest and I switched entirely to interviews.

Since then I’ve written and published adventures and supplementary rules for Dungeon Crawl Classics RPG under the Stormlord Publishing banner, such as the Black Powder, Black Magicseries, Prayers of the Forgotten, and the hexcrawl island adventure The Treasure Vaults of Zaddabad

Now I’m working on The Ruins of Wytchburgh: 1666 which will be compatible with old-school games.