A collaborative megadungeon experiment for the Classic Adventure Gaming community
I’ve been mucking around with Gary’s Appendix A and a large pad of A2 sized graph paper. What started out as a bit of fun generated something that looked particularly interesting. Particularly gameable. Perhaps the first level in a massive AD&D megadungeon.
Once this was created and I surveyed the size of it, I soon found that I wouldn’t have nearly enough time to key all these rooms. The map sat on my desk for a little while before I had a bit of a brainwave. Perhaps I didn’t have to key this beast alone. After speaking to GusB from the Classic Adventure Game Podcast, I thought I would ask members of the CAG community to have a crack at keying this beast and see what they could come up with!
And so, I’m launching a project that I hope will be both fun and useful for the wider Fantasy Adventure Gaming community: to create Level One beneath Castle CrAG.
This will be a collaborative design effort, where contributors submit keyed rooms that I will then collate, edit, organise, and publish as a complete AD&D/OSRIC-compatible dungeon level. Once the text for this level is finished, it will be placed within my existing campaign world and immediately put into play for testing.
I’ve already begun sketching out the lower levels of the megadungeon, and I’ll soon begin inking Level One — so this is the perfect time for the community to jump in and help bring it to life.
What This Project Is About
The goal is simple:
To create a massive and classic AD&D Dungeon Level for the community, by the community.
This will be published as a free resource for others running AD&D or OSRIC.
Castle CrAG: What is it?
The concept of Castle CrAG torn from the heart of Adventure gaming: the Megadungeon below a Castle. This goes back to the formation of the hobby. The linchpin of any Fantasy Adventure Campaign is the multi-level, multi-themed, multi-faction, megadungeon. Think of Castle Greyhawk and Castle Blackmoor. It is something that can sit within a days journey from your campaign’s central city, somewhere PCs of any level can go to delve and gain treasure. A place ripe for adventure.
For the moment we will be focussing on Level One of the megadungeon. A sort of litmus test to see if the project is feasible.
The THEME of Level one is FACTION WARFARE.
The dungeon itself sits below a Ruined Castle constructed during the darkest recesses of antiquity, and is famed for its evil and corrupting influence. The castle ruin proper is currently controlled by a high level magic user and their army of goblins. But this MU has been poisoned through assassination, and their grip on the castle wains. This is by design, for control of the castle ruin is in constant flux.
There are powers in the lower levels of the dungeon who manipulate the monsters of level one, and the castle ruin. They draw them forth en mass, with dark offers and promises. They encourage open warfare for supremacy of the level; for each Winter Solstice, a herald of the powers below – a powerful Anti-Cleric named Kal-Thule – ascends the great staircase (Key 1) to gift the supreme power of level one with a magical item of power. With this, they are granted licence to capture the castle ruin above and hold it for another Solar Year. By this scheme, the powers below have attempted to guard and obscure their plots with a layer of brutal and scheming upstarts.
The agents of this lower power gain passage through the dungeon with the presentation of a yellow rune, one that all come to respect and fear, for challenging it’s right spells doom.
The nature of these lower powers, and their machinations, are currently not the focus of the project, but they should certainly be in your mind as you design the your factions and denizens.
The ARCHITECTURE of Level one is as follows:
- The North West quarter of the map is the FORGOTTEN HALL OF THE FACELESS ONE. This area was once a temple complex dedicated to Nyarlethotep in his form as the Faceless Pharaoh. Though perhaps no cult currently resides here, his statutory may still be present, even if defiled and forgotten. Corridors are generally 20’ tall and made of cleanly cut granite blocks. Arches are square and pillared in the Egyptian style.
- the North East quarter of the map is the QUILL SECTOR. Long ago this was an administratum, but most remnants have been smashed away during constant battles through the years. There may still be some evidence of bureaucrat veneration, though perhaps graffiti mocks this openly. The corridors are generally 10’ tall and walls are barely covered with an ancient plaster, fallen to ruin. Arches are vaulted and capped with the brooding faces of scholars long forgotten.
- The South West quarter of the map is the HOLLOW OF FORGOTTEN TRUTHS. Long ago this was some sort of reeducation centre. There are hints that an elemental cult or Old Way Druid faction overtook the area and constructed elaborate testing rituals here, but what they were have been lost to the sands of time. Constant war has blanched much of that away. Walls are rough and often constructed of field stone, the ceilings are 15’ tall.
- The South East of the map is the BLEAK BARRACK. Warrior veneration and tableau’s of black mailed warriors are generally scattered throughout. Alcoves with black candle sconces offer prayers to long forgotten dark warriors, as are their charnel reliquaries. Ceilings are 20’ tall but vaulted. The walls are generally constructed of small bricks and archways are vaulted with capstones of gargoyle faces.
- The central area around Key 1 are hewn from large basalt blocks, and much foot traffic and evidence of passage are always found.
Project Guidelines
To keep everything consistent and faithful to the old-school spirit, I’ve established a few ground rules:
1. No AI Use
All contributions must be entirely human-made.
2. Greyhawk-Compatible Tone
The dungeon should match the assumptions of AD&D’s implied setting:
- Fantastical medieval culture
- Sword & Sorcery atmosphere
- Classic monsters, magic, and treasure
Nothing too gonzo, sci-fi, or anachronistic. No new monsters.
3. Dungeon Level One
If Castle CrAG is a successful project, there may be more levels in the future, a true megadungeon. But for now we will focus on Level One and see what evolves.
When you submit your room keys, please keep monsters, traps, tricks, and treasure appropriate for low-level adventuring.
Don’t worry — higher levels will come later.
4. Licensing & Rights
By submitting a room, you agree to allow me to edit and publish your work . I will publish Castle CrAG under a CC BY-NC-ND 4.0 licence.
This means:
- You will be credited as the author of your room.
- The finished dungeon may be shared for free, anywhere.
- No one may sell it or alter the final document.
- My editing is for purposes of consistency, clarity, and layout only.
This keeps the project non-commercial, free to the community, and protected from misuse.
How to Contribute
If you’d like to participate, simply fill out the submission form:
This form collects:
- Your room key number
- Your description and details
- Monsters statline
- Your author credit information
- Your agreement to allow me to publish the above.
The form will send the data to a spreadsheet that can be viewed in real time. This means that submitters can see what keys are free before starting to write and we can avoid duplicate keys.
There are plenty of rooms open — and I’d love to see the creativity of the CAG community shape this doomed, ancient place. Here are the roughly numbered maps. The Map with colours show faction areas of control:
You can view the Live Room keys here if you are a member of the CAG discord: https://discord.com/channels/1159906922032537611/1442569772813389954/1445850914580856832
Join In — and Let’s Delve Together
I can’t wait to see what the community contributes — and I’m looking forward to bringing your ideas to life on the page, inked and ready for the next band of adventurers.
Oh, and Dungeon Levels need empty rooms too! Don’t forget to submit them.
Dreadlord Games 