Wednesday 3 April 2019

[STUFF] The Dungeons of Morthimion

[Players wishing to adventure in Castle Morthimion: STAY AWAY!]

Work in Progress
Inspired by reading the recently published Black Maw dungeon levels, and playing in a friend's S&W-based game, I was once again bitten by the megadungeon bug. I started putting some thought into running a canonical OD&D dungeon exploration game – the proverbial huge ruined pile built by generations of wizards and insane geniuses. Nothing Castle Greyhawk-sized (thus, not something that would accommodate multiple parties playing 24/7), but hefty enough to feel expansive and mysterious, and true to the tone of the three booklets. To avoid overreach, and give myself some structure, I decided to stick to a brief keying style I experimented with in Zuard Castle, an older thought experiment (but with just a bit more detail). In fact, Zuard Castle became the base for the dungeons of Morthimion.

My general idea for the dungeon structure is based on six main levels (of which five are depicted here). The background idea is that the sixth level is a kind of dimensional interconnector, dumping hapless critters from all over down in the deeps, which battle each other, and gradually filter up to the surface through passages and gates, menacing the surrounding lands. Morthimion Castle was abandoned to its fate when the mining operation underneath hit the monster motherlode, and has pretty much gone to the dogs since - now occupied by a senile and dangerous 11th level Wizard and his retainers. (In a world which otherwise has a limit at LVL6) The surrounding forests (to be mapped as a wilderness maze, pointcrawl-style) are so bad that they are separated from the civilised lands by a Hadrian's Wall kind of construction. These woods are a first testing ground for the adventurers who venture from the civilised lands.

General Level Plan
The dungeon levels are fairly self-explanatory, with multiple themes, and a number of interconnections. I am particularly interested in developing the "Sideways Level", a vertical environment populated by flyer types, and allowing for some interesting dungeon tactics. Another central feature of note is a grand staircase to levels III and IV, but one which has a 1:3 chance to transform into a one-way slide. Multiple secret levels, reached after the ways of accessing them are learned, are planned (some within the "ruined pile" itself). Keying is much more dense than the Greyhawk standard (to compensate for the fact that we don't play as much as the Lake Geneva crowd back in the day), but the notes are fairly light.

I currently have most of the map for the first and second levels. Following tradition, the first level is a mixture of storerooms, jails, magical enigmas, deathtraps and other things you would find in a realistic castle basement. The openings in the walls are doors, and the rectangular symbols are heavier gates (the kind you roll for to lift). The initial entrance is through a dry well in the courtyard, with a tithe extracted by the Wizard's henchmen. The Level II stairs are to the north and south, the former behind a locked gate, and the latter controlled by a large robber band. I have tentative plans to use the empty space for further development, probably accessible from down below.


The Dungeons of Morthimion have already gone through a trial by fire testing round. I originally intended to slowly sketch out a few levels, and stock them in fits of inspiration in a piecemeal fashion – the scrap of paper idea collection phase if you will. Then, 23:30 Friday night, I realised I had forgotten to bring along my regular campaign folder, and the game would be on Saturday afternoon. Ooops. So I got up Saturday morning, had breakfast while numbering the rooms, then wrote the damn Level 1 key between 8:00 and 11:30 – the time I had before packing up for the afternoon and having lunch. This kind of creative pressure (recalling the immortal tunes of Crash Dive on Mingo City) tends to be good for me, because I took my notes and map, along with a printout of Greyharp's single-volume OD&D book, and we had a great time.

Level 1
Since they were very brief, I typed up my notes and created an annotated map last night, and am posting it for your interest down below. This is rough stuff, pretty much verbatim with the bare minimum of clarifications (mine had a bit more monster stats – you can find them in the OD&D booklets), and a two-paragraph background. I may clean it up later for publication if we get there, maybe, but it will remain in a terse, focused format even if I do.


I am really proud of my players – they were dying left and right in Castle Xyntillan, but those lessons proved useful. Here, they survived with a single casualty, who froze to an ice statue while trying to extract a precious gemstone from a stone head (as the old wisdom goes, “The risk I took was calculated, but boy, am I bad at math”). They moved quickly, made snap decisions, avoided risky fights (I kept rolling powerful monsters who had come up from the lower levels), and were quite successful at finding the good stuff, including a 6000 gp crown. When all was said and done, they had mapped perhaps more than a third of the level over two expeditions. Random findings/remarks:
  • Some monsters play more of a channelling/blocking role, restricting player movement through the dungeon.
  • Stuck doors (and doors becoming stuck again) are a vital part of OD&D, and opening them is a major time sink / random encounter risk.
  • Damn right you need encumbrance rules, and bulky treasure. By the end, they were considering if they could haul out a particularly heavy marble throne.  :D
  • I did reduce random encounter numbers, not wishing for battles with 300 orcs. I swear there was a note in OD&D about the same, but the game's organisational issues being what they are, I couldn't find it.
  • A cluster of storerooms ended up containing several instances of cloth, rugs and tapestries, and were promptly dubbed "The Crypt of Karl Lagerfeld".
  • They found, but didn't attack a band of 50 bandits, even though they were then 14-strong. Smart thinking, although they may have done it with some losses.
  • Charm person became very useful in recruitment.
  • Creative problem-solving: finding out if an insane hermit is chaotic or just disturbed by walking him to a nearby chapel of Law, and forcing him to pray; buying a ball of yarn to put the spirits of dead kittens at ease.
  • About the dead character who had died for a gemstone: “He has gifted us with more than 500 gp of profit - by dying, he relinquished his share of the loot.”
  • They first thought their initial 900 gp haul (after multiple rooms with no treasure) was exceptional. Being reminded of the XP rules, they reassessed their priorities and became even more efficient at finding, evaluating and transporting treasure.
  • There were two characters per player, plus henchmen. A single player opted for one 2nd level PC, a Cleric with 3 Dexterity and 2 hit points. He survived the expedition.

The characters:
  • Xang, Fighter 1
  • Xing, Thief 1 (a concession to new-school D&D!  :D The only casualty.)
  • Tycho the Ascetic, Cleric 1 of Light
  • Weirlord, Magic-User 1
  • Xingar, Fighter 1
  • Fatalgor, Thief 1
  • Brutus, Magic-User 1
  • Rianh, Fighter 1
  • Brother Tivold, Cleric 2 of Light

Their henchmen:
  • Ruphart the Guide (acquired via charm person because he didn't want to come down to the dungeon - no honour among murderhobo scum)
  • Sanislo, light foot
  • Wul, light foot
  • Morton Melf, Elf 1 (freed captive)
  • Lydia Luckless, Thief 1 (freed captive)

Download: Castle Morthimion - Level 1 (1.7 MB PDF)


  1. Map looks great! Have DLed for more study.

  2. But what does the GREAT STONE FACE do?! You wrote its name in capital letter, there must be a reason for that!

  3. Sweet key!
    You have yet again inspired me to continue working on my own dungeon.

  4. Looking forward to more!

    @Tamás Illés: perhaps it's an homage to Gygax's GSF?:


    1. That's correct. Also, I originally wanted my own Enigma, but slotted in the Great Stone Face because I could not think of anything original in under 5 minutes, and time was ticking. It may or may not be replaced with something more original at a later point. :D

    2. I thought of Grimoire's stone faces first, since it seems to be a part of the wall based on the map. I will probably go with that if I even run the module.

  5. I like this stuff on so many levels... speaking of levels, i'm putting this in my campaign as soon as all of them are ready. :)

  6. Awesome! I linked people to this and your zine today. Can't wait to see where this megadungeon goes.

  7. We are having a grand time with Morthimion. Have run it now half a dozen times or more. Thanks for sharing this little gem with us all.

    1. Really cool to know you are getting something out of it! There is more to come here - hopefully soon!

  8. I totally missed what you were doing here (I thought your posts were just play reports) What a cool project. How are you determining monsters and treasures? Are you using the various 3lbb tables for that?

    1. Yes, this is a deliberately close-to-canon LBB-only campaign (with slight liberties). For every level, I devised some rooms on the basis of ideas I already had, then filled out the rest via semi-random generation (random rolls, slightly corrected not to clash too much with what was already there). My formula was a simple 1d6: 1-2 monster, 3-4 empty (potentially minor detail), 5 trap, 6 special.

      I picked most of the "filler" monsters with the vol. 3. Monster Matrix. This is a great table, since it "dips" into the lower levels, providing good variety. Monster numbers were rolled on the basis of feel (since OD&D is ambiguous on this matter), except for major lairs, where I just used the vol. 2 numbers.

      I generated the major monster lairs with the vol. 2 letter-coded treasure types, and stocked the smaller rooms with the vol. 3 Distribution of Monsters and Treasure matrix. However, I cheated here a bit, bumping up treasure by one level. OD&D was played 24/7, and we no longer have that luxury, so the gold must flow a bit more generously. This is also why empty rooms are less common.

      I've already got the third level and part of the wilderness done, and hope to post it one of these days. We have not played this campaign this year yet, since it is mostly for those sessions when key players cannot make it.

    2. Had some time to look through the levels you have posted so far Melan and I am loving it. One suggestion regarding layout - it would be helpful if you spaced between room entries - the page looks like one giant block of text.
      The other thing - maybe as an appendix when you are done - would be a brief description of the new monsters. I have no idea what a trome is. Easy enough to replace with a familiar name or simply make up, but it would be nice if you provided a description somewhere. :)

    3. Thanks! Yeah, this is all very raw stuff - unformatted table notes, essentially. The published version, when it comes to that, will be easier on the eyes, although it should preserve some of the OD&D roughness. But spacing will definitely be changed.

      I think you already know tromes, although under a different name. :) Here is how OD&D describes them: "A cross between Gnomes and Trolls (. . . perhaps, Lord Sunsany [sic] did not really make it all that clear) with +2 morale." The new name is to clear away the associations accumulated by decades of game history - these are gnome/troll hybrids, not hyena-men!

      The other new monsters will receive an OD&D-style treatment in an appendix.

      Of course, these are still shared playtest notes. Mind the Greyhawk Construction Company signs! :)

  9. That's totally Awesome. Weird how 40+ years after publication setting up a basic btb 3lbb dungeon is something of a novelty. Great stuff.