15 June 2020

grodog's Favorite Mega-Dungeons

Some info about my favorite mega-dungeons, from the classics to the newest, hot-off-the-presses OSR titles (well, "new" as of today, 15 June 2020 anyway....). 

This post was inspired by some discussions over on the Astonishing Swordsmen & Sorcerers of Hyperborea forum, as well as a similar thread over on TheRPGSite.   The questions raised in those boards were:
  • Which mega-dungeons do you like, and why? 
  • Which mega-dungeons have you used in play?

The Quilt Map -
Map by Tony "Wheggi" Rosten

grodog's Thoughts on Well-Designed Mega-Dungeons -- The Stuff that Matters at the Table

I think that for me what I like about a mega-dungeon really varies, based on who I've been playing with (or sometimes, working with).  I've really enjoyed nearly all of the mega-dungeons that I've played in or run, but I've also generally had the wonderful pleasure of excellent DMs and players, which makes all the difference in the world in terms of the game experience at the table.

Thinking through the mega-dungeons I'm familiar with, the stand out qualities that I love to play through, and the mega-dungeons that bring that to the table are:

  • Best Environments to Explore and Map:  Castle El Raja Key, Maure Castle, Caverns of Thracia, Foolsgrave
  • Most-Fun Encounters:  Castle Greyhawk, Foolsgrave, Rich Franks' mega-dungeon
  • Most-Fun Puzzles, Enigmas, and Centerpiece Encounters:  Castle Greyhawk, Maure Castle, WG5, ASE1/2-3, Undermountain
  • Coolest MapsArden Vul, Castle of the Mad Archmage, Foolsgrave, The Quilt Map, Undermountain, Vladikavkaz 
  • Best Presentation in Print:  None*
  • Pulls It All Together:  Caverns of Thracia, Foolsgrave, Maure Castle, Tomb of Abysthor

* In terms of best-published format/presentation for a mega-dungeon, I don't think that we've seen any stand-out products deliver on the goods on that yet.  Necromancer Games build out a good standard template for dungeon levels between Rappan Athuk and Tomb of Abysthor, and The Grand Temple of Jing attempted to design a new layout format for the mega-dungeon (similar to what Ptolus attempted for the massive-city sourcebook), but neither product quite achieved their overall goal on those fronts, due to other, over-shadowing issues with the products (horrible maps in RA the first go-round, while the KS version of GToJ didn't really pursue the usability goals of the first version of the dungeon).  

A well-built layout focused on at-the-table usability, married to a brilliant  book design could really distinguish a future mega-dungeon product, and potentially allow it to leapfrog into the top of the list....


Castle Zagyg - Mouths of Madness and The Storerooms
Dungeon Level - Cartography by Jeff Talanian

Mega-Dungeons grodog has Played

  • Castle El Raja Key - written and DM'd by Rob Kuntz (pre-published version)
  • Caverns of Thracia - written by Jennell Jaquays, DM'd by Jon Hershberger
  • Dark Tower - written by Jennell Jaquays, DM'd by Jon Hershberger
  • Foolsgrave - written and DM'd by Chainsaw (pre-published version)
  • Jakallan Underworld - written by Phil Barker, DM'd by Victor Raymond (pre-published version)
  • Thieves Fortress Badabaskor - written by Bob Bledsaw & Mark Summerlott, DM'd by Jon Hershberger

Mega-Dungeons grodog has Run

  • Castle Greyhawk - grodog's version/The Lair of Thelmon Onvalth - my own version of Castle Greyhawk (pre-published version)
  • Castle Greyhawk - EGG and RJK - Bottle City, EX1-2, WG6, etc., etc.
  • Castle El Raja Key/Maure Castle - RJK - WG5, The Statuary, Chambers of Antiquities, Warlock's Walk (co-DM'd with Rob Kuntz at GenCon 2007)
  • Mythrus Tower - Matt Finch
  • Temple of Elemental Evil - Gary Gygax with Frank Mentzer
  • Tomb of Abysthor - Clark Peterson and Bill Webb 
  • Undermountain - Ed Greenwood - Box set 1, Dragon articles

Bottle City level of Castle Greyhawk -
map by Rob Kuntz

Mega-dungeons grodog has Helped to Design, Develop, Edit, and/or Publish

  • Castle Greyhawk - grodog's version/The Lair of Thelmon Onvalth - my own version of Castle Greyhawk, including my version of The Black Reservoir (based on EGG story vs. RJK level) and The Quilt Map (based on Tony Rosten's map)
  • Castle Greyhawk - RJK - Bottle City (editing, development)
  • Castle of the Mad Archmage - Joe Bloch (editing/development work abandoned when Black Blade contract expired and Joe pursued publication on his own)
  • Maure Castle - Warlock's Walk - RJK (editing)
  • The Twisting Stair centerfold mega-dungeon - Tony Rosten and Allan Grohe
    (editing, development)

Oerth Journal # 23 -
dedicated to Maure Castle

Mega-Dungeons grodog has Read but Neither Run Nor Played

  • Anomalous Subsurface Environment - Patrick Wetmore - Levels 1 and 2-3
  • Arden Vul - Rick Barton (pre-published version)
  • Barrowmaze - Greg Gillespie (first versions from Kickstarter, prior to expansion in Barrowmaze Complete)
  • Castle Blackmoor - First Fantasy Campaign as well as the 3.x versions
  • Castle Greyhawk - Castle Zagyg, WG7, WGR1, Expedition to the Ruins of Greyhawk, etc., etc.
  • Castle Xyntillian - Gabor "Melan" Lux
  • The Darkness Beneath - many levels published in Fight On!
  • Dwimmermount - James Malizewski
  • The Grande Temple of Jing - Danny O'Neill & Diverse Hands
  • Mines of Khumar - Stefan Poag
  • Rappan Athuk - Clark Peterson & Bill Webb - R1-3, Rappan Athuk boxed set (original)
  • Ruins of Kwalishar - Tim Kask (pre-published version)
  • Stonehell - Michael Curtis - Vol 1: Down Night-Haunted Halls
  • Undermountain - Ed Greenwood & Diverse Hands - Box set 2, the Fireplace level (Dungeon Magazine), a smattering of modules too
  • Vladikavkaz - Keith Sloan (pre-published version)

Castle Xyntillan - by Gabor Lux,
Cover art by Peter Mullen

Mega-Dungeons grodog has Neither Read Nor Played

  • Arden Vul - Rick Barton (final/published version)
  • The Black City - from Dreams in the Lich House blog 
  • Castle Triskelion - from eponymous blog
  • DCC #51 Castle Whiterock - Goodman Games
  • Forbidden Caverns of Archaia - Greg Gillespie
  • Gunderholfen - G. Hawkins 
  • Highfell: The Drifting Dungeon - Greg Gillespie
  • Mike's Dungeons - Geoffrey McKinney
  • Numenhalla - published serially in Megadungeon magazine
  • Stonehell Vol 2: Into the Heart of Hell - Michael Curtis
  • The World's Largest Dungeon - AEG

If you know of other mega-dungeons that I should check-out that don't appear in the lists, do please chime in! :D



  1. My top 3:
    Grande Temple of Jing
    Rappan Athuk

    Megadungeons I have played or run
    All of the above
    Mord Mar (my personal)
    Mythrus Tower / Jordoba
    Grodog's Greyhawk (3 sessions/adventures)
    Castle Zagyg (1 session, own most)
    Temple of Elemental Evil
    Castle of the Mad Archmage
    Others I am sure that I am forgetting

    1. Thanks Rocky!---hopefully we'll get to roll some dice again in the future, in person :D


  2. Module B4 The Lost City is a megadungeon, though it only sketches out the lower levels, leaving the detailing of them to the individual DM.

    1. I wrestled with whether to include one in the lists. Will go back and take a look again, thanks!


  3. I really think you're selling AEG's "World's Largest Dungeon" short. IMHO, it definitely makes the grade for "best example in print".

    1. I'll take a look, thanks for the recommendation.


  4. Cha'alt! Also, Liberation of the Demon Slayer... both by me, Venger Satanis.

  5. Arden Vul is an absolute mess to try and run because it's simply too big with too many factions. So bad I sold it immediately after reading. The printed maps are the worst I've ever seen in a published product because they apparently did nothing to scale them correctly.

    Thracia gets my vote as the most over-rated "mega-dungeon" ever. Nothing special about it at all, beyond being old.

    Barrowmaze, Archaia, and HighFell are all good. We've played and enjoyed sections of all of them. ASE is fun as a gonzo foray. I like how Rappan Athuk reads, but haven't played it yet. Not quite as enamored of Stonehell, but it gets the value award for its amazing pricing for the amount of content one gets. But I find mega-dungeons kind of a slog to run if you can;'t play a lot. So they're actually more interesting to read in my opinion.

    1. Thanks for the input. I've not played AV but have read through early drafts, and love Andreas Claren's map work on the levels.

      I'll have to disagree with you on Thracia: when I played it, the levels were evocative and fun to explore, but some adventures don't click with everyone: in our crew, one of the players quit over Thracia....

      I haven't looked at Greg's two later books, will check them out (and added them to the list based on your recommendations here, and other folks too).


  6. Mike's Dungeons, written by myself. It's on drivethrurpg.

    1. Added, thanks for the reminder Geoffrey.


  7. Nice review Allan. Neat there are so many out there these days.

    1. We do live amidst a mega-dungeons renaissance, regardless of how you define "OSR" :D


  8. Interesting reading, I had never heard of the quilt map before. I ran a short bit of Stonehell and and I'm a player in Barrowmaze at the moment. Stonehell was pretty easy to read and run, but I didn't care for the content of the canyon and the central entrance. If I were to play more of it I would add several new ways to get inside the dungeon. Anyway, who is this Hershberger, and how do i get in on one of his megadungeon games? lol ;)

    1. Jon lives here in Wichita, and is the founder of, and my business partner in, Black Blade Publishing.


  9. What a great post! Missing though is a definition showing what led you to include those choices. For my money, a megadungeon must have a minimum of six levels (vertical or horizontal areas) and must not be something players can clean out. IOW, a party could return to the place repeatedly for new adventures.

    By the above definition ToEE is not a megadungeon but B4 The Lost City certainly is - maybe the only megadungeon published by TSR until Dargaard Keep DL16. (I'm not too familiar with Dargaard, but its seems to fit the bill).

    1. Thanks Dan! That's an excellent point, and I should probably extract some of my "best" design criteria from my Castle Zagyg review, and from other various and sundry scribblings and create another post on the topic! Until then, however, here are some stand-out qualities to me:

      - "mega" dungeons = big enough to get lost in, no matter what levels the PCs are (almost anyway), and sufficiently large that the dungeon cannot ever be fully-explored or "beaten"---this makes Caverns of Thracia and ToEE and B4 as small as or smaller than I generally consider applying the label "mega-dungeon" to, on most days
      - inspires me to expand upon the baseline content: Gygax and Kuntz are both particularly good at this
      - a wide-variety of types of challenges within it, running the full gamut of encounter types, with varying levels of challenge within a level, and across levels
      - a place that can serve as the entire hub of a campaign---a campaign dungeon, to use T.Foster's excellent term
      - a place that each DM puts their own stamp upon, that is inherently their own expression of "dungeon-ness" and "fun-adventure-ness"

      I'll add DL16 to the list of ones to check out sometime, Dan: I'm not deeply familiar with DL after the first few books and first 6 modules. Thanks!



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