OSR: Imperial Megapalace - Rapid Dungeon Assembly

On Saturday, Feb. 1st, the Pirate group TPK'd to beetles (and greed).
On Sunday, I despaired at the need to find a new genre, system, or plan. The Pirate game, after two TPKs and many hijinks, had run its course.
On Monday, I decided to write a Byzantine megadungeon.

Next game is scheduled for Feb. 16th. If you're in that game, look away! Spoilers abound.

Here's either how I wrote a megadungeon in two weeks.... or how I failed miserably.

Step 1: Concept Map

I picked an approximate layout. A round fortress-palace with four towers and a central dome. Crypts and a cistern underneath.

Then, I started tossing rooms onto a piece of paper. I went through existing palace maps (real and fictional) to find common rooms. Adjacent sections overlap or are placed nearby.

Ideas started to solidify. The dungeon would initially have one entrance, but more could be found and opened. Each tower would be guarded by a classic mythical beast. The dungeon will be a testbed for the Monster Overhaul, full of creatures and reskins for convenient playtesting.

Step 2: Draft Map

I decided to map the dungeon in Sketchup. It's not an ideal mapping tool, but it does have some handy features:
-ease of rotation

-components (items that can be cloned, but editing one item edits them all)
-ease of checking sightlines and overlap of complex regions

Starting with the south tower and working outwards, I started mapping rooms and zones. I didn't worry about assigning specific functions or occupants to every room. That can come later.

I did start planning routes. Assuming the players enter from the south, where can they go? What will bottleneck them? Is the dungeon sufficiently jaquayed?

I imagined a party moving through the dungeon. What would they see? Where would they go? What about the dungeon's original inhabitants? How would they use this space? Would an Emperor share a corridor with servants? What would diplomats see?

Mapping the dungeon will be a challenge. I'll probably provide players with template maps or approximate scribbings, or let them map it pointcrawl-style.


Step 3: Stocking Maps

Main Level
Upper Level + Towers
The map is very heavily jaquayed. Some sections are linear or gated, but the bulk of the dungeon is criss-crossed with multiple paths, weird loops, and interesting choices. Secret doors are often one-sided (one side is hidden, one side is obviously a door). If approached from one side, they can create a shortcut back to a previously explored area.

The clock tower (the north tower) has two rotating sections. The bottom section rotates as players discover keys or gears. The upper section rotates on a 1 hour timer.

I want a mix of small and large rooms. Fights should require manuvering and flanking. Give players space to stretch out. Engulf them in the majesty of the Last Emperor.

At this point, the maps are ready to be stocked. They are
still drafts. As I stock them, I'll remove and edit rooms, make notes, and scrawl corrections. 

Step 4: Stocking Subsections

I like minimaps. They make running complex dungeons much easier.

I am currently cutting the main map into sections. 3 are present in the image above: the South Tower, the Hippodrome, and the Menagerie.

Numbers are assigned based on probable routes players will take. To minimize flipping, each section will have its own half page, whole page, or 2-page spread.

I'm also writing very brief room notes as I assign numbers. No evocative prose, no details, just "gate" or "manticore" or "trap." If I have details I add them, but at this stage it's better to get the content down. I can always punch up the prose after playtesting.

This section takes ages, especially if I have to renumber a section or find I've missed a critical room. Splitting the dungeon into subsections helps.

Next Steps

Stock, stock, and stock some more.

If you've got ideas for things that lurk in the Imperial Megapalace, let me know in the comments.
I can't guarantee I'll take your suggestion (or any suggestions), but it can't hurt to throw ideas out there. Procopius might help.

I'm not sure if this dungeon will become a free product, a Patreon exclusive PDF, a paid Kickstarted thing, or something else entirely. It depends on how the playtest goes, how much I like the final product... and if I get it finished in time.

Scratchpad Notes

To Do

-d100 Encounter Table
-I Search the Body
-d50 / d100 table of backgrounds (not using -lings this time).
-review these tables (good work, past Skerples) and use them.


The Last Emperor
-Anyone who eats his flesh becomes sort-of immortal.
-Also cursed. A lot.

-Regenerates, but is weak.
-Built an Artificial Hell under the palace to torment enemies. Also serves as a regeneration point if he is killed.
-With blind tigers.
-Possible to negotiate with but far easier to avoid.

-Probably the first "big" monster the PCs will meet.

-Guards a path up to the Royal Prison.
Twisted Giant

-In the cathedral. A bishop grown large. Wields a censer.

-Twins. One in the Prison Below, one in the Prison Above.
-In the west tower. Pick off creatures who scale the walls.
Hereditary Eunuchs
-Don't ask.
Ketolysis Monks
-Flame breath from ketogenic starvation.


  1. Ideas I've been tossing around myself:

    wooly mammoth with gigantic pale human feet, with two trunks and one extra foot at the end of each trunk. Vulnerable to tickling.

    add a poem somewhere containing "clues" in the style of Tomb of Horrors. could just be for one subsection of the palace, doesn't have to refer to the whole thing...

    monster referred to only as "the wugalaboo" that wears long muddied silks and a horrifying mask. it's got a fearsome reputation but will be easily defeated by the PCs. underneath its mask, it will resemble the mother of the PLAYER whose character landed the killing blow. or, if the players somehow unmask it while it's alive, it'll resemble YOUR mother.

    just a labrador or other nice sort of dog, with a bloody cross scratched into its forehead. attacks on sight. idk what's the point of this one honestly but I like the imagery...

    Good luck!!!

  2. Some ideas for things that lurk:

    Supercharged breed of racehorses. Prone to exploding.

    Sumptuary law enforcers, will harangue/beat you for dressing, eating, or speaking too fancy.

    A gaggle of concubines in aphrodisiac-induced maenadic frenzy.

    Crowns/thrones stolen from conquered kingdoms, imbue knowledge of the emperor's palace, forces, or weaknesses if worn/sat on, but this risks possession by psychic gestalt of royal lineage.

    Trained dancing apes, set their initiative order by the tempo of ambient music. Prone to face-ripping-offing rages if you can't match their moves.

    Undead skeletons of labourers & architects buried alive in the secret passage/vault they just built to protect knowledge of it.

    Cadet branch of imperial line, kept around in basement for spare heir without posing threat of pretender. Degenerated into incestous troglodytes, not evil but have very skewed understanding of how things work.

    Envoy from foreign star, being of strange light trapped in palace until repairs are made to telescope/projector in astronomy area.

    Magic bathtub of stasis, soaking in it delays any ongoing wounds/poisons/curses/aging until the water goes cold or splashes out.

    Enchanted/cursed history book that changes to flatter the reader's preconceptions to the point of narcissistic obsession.

  3. Ideas:
    Varangian Guard! A bunch of hairy northerners with huge axes and a penchant for carving runes on things.

    Chapel defaced by said Varangians, marble walls and pillars are now covered in rune carvings and serpents. Serpents have animated and sliver about on the wall like angry 2-dimensional asps made of negative space. One of them is chewing an icon.

    Icon-painter’s attic/basement! Full of valuable but difficult to transport icons. Also contains a locked backroom full of the Forbidden Icons, such as Saint Liryc the Non-Euclidean, Saint Aglo the Hall-Burner and Saint Lisab the Blinder.

    Ghost chariot reenacting ancient Blue vs Green rivalries.

    Falxes. Just big blades on sticks.

    1. All things I already had listed (in one form or another; the chapel is good). But still excellent!

  4. Ancient trophy rooms full of old imperial hunted creatures, animated by dark sorcery (tm). Deer heads that snap at you. Centerpiece is the remnants of a dragon, split into several peices.

    Animated baboon skins
    Lizard teeth knives
    Massive Roc claw pulling it's away along the corridor, guided by the screams of the different bird heads nailed to the walls.

  5. That is a great map. Been looking for a good 'Lost Citadel' map to use in a game next month. I might very well repurpose this myself with your blessing.

  6. That is a fantastic map.

    Two comments:

    1: I sure am looking forward to reading the pirate campaign playthrough

    2: This is the second time you've put tremendous effort in a setting only to have it TPK on you. Is this becoming a concern for you?

    1. 2. Not at all. I think it was a 20+ session campaign. Pretty decent.

  7. As far as things lurking... A small troupe of goblin merchants. They have a truce with most inhabitants and supply them with things from outside, or other inhabitants. Not hostile, but full of nasty tricks for would be thieves.

  8. A flameskull - the head of the last person to betray the last emperor, decapitated and cursed before the fort fell.

    A swashbuckling reforming skeleton (or group of skeletons even better), sworn to defend the fort. Named after Giovanni Giustiniani and his mercenaries.

  9. these maps are gorgeous. reminds me of the ship in expedition to the barrier peaks.

  10. Here's one. Inhuman concubines lounging in a bath of mercury. They invite the PCs to join them, only rolling on the reaction chart if denied. A PC who enters the bath has to resist the mercury as poison, if the save succeeds they gain some kind of bonus and some advice/rumor/secret.
    The concubines will also accept gifts, and if flattered and fawned over enough, may also devulge said information.
    They appear as unearthly beauties, but with empty eyes and jagged broken smiles, and will attack if you dis the Emperor.

  11. I don't know just what feel you're going for but I can hook you up with a good source of monstrously inbred nobility- http://www.scp-wiki.net/scp-082.
    Imperial harem and heirs should be present. Nymphs maybe, or just some sympathetic type hostage ladies?