Picking things back up on this project, let me set out some system assumptions as a baseline for adding mechanics:
Assumed PC Party: 3-5 PCs of Level 1-3 (approx. 8 total HD)
PC Hit Dice: Average 1d6+0/level
Melee Weapon Damage: 1d4 to 1d10
Currency/XP: silver standard, 2000/4000/8000 total XP for fighters to level
AC/Saves: per OED (as a tip of my hat to Paul for inspiring this whole endeavor)
Item weights in stones (1 stone = approx. 10-15 lbs), assuming 5 general items = 1 stone
Scale: 1 square = 10 feet (or 1 hex = 10 feet across flats), 1 turn = 10 minutes, 1 round = 10 seconds
Ability Score Recovery: 1 point per day, from random score if multiple are lowered
Let me also establish the general conditions of the nest:
The walls are a mix of soil, stone fragments, and metal waste (similar to soft stone for tunneling, etc.). Ceilings are generally 5 feet tall, hindering large weapons. Openings at keyed choke points reduce to 3 foot diameter. Floors are uneven but not treacherous. Secret doors are soft/thin walls that can be broken into a choke point with 1d6 turns of noisy axe/hammer/etc. work (time halved with proper tools, time doubled to make full opening). The air is humid; smells of mold, rust, and organic decay; but has adequate circulation to avoid trapping gas. Millions of normal termites and ants live in the cracks and crevices of all surfaces except on top level, crunching under every step and causing a constant drone of scuttling as they wage their war; they leave active characters alone, but attempts to rest require a save vs. stone every hour to withstand the irritation as they crawl under armor and clothing. There is no light except from sunlight near exits.
That last point feeds off of all inhabitants except the faerie being uninhibited by total darkness, which I'll need to remember to note when it comes to NPC stat lines.
Moving on, setting the assumed PC party means I can set the total treasure value for the nest. For a medium-sized dungeon like this, I like to take the XP required for the middle party assumptions (so 4 PCs needing 4000 XP in this case) and allow for 2-3 times that total. With this dungeon, I'm thinking much of the treasure is going to be heavy for its value (mostly raw metal and the like, rather than jewelry and gems), so I'd err on the high side of that range to make decisions to leave weight behind less punishing: perhaps 46,000-50,000 sp-value in total. In the last post, I picked out eight valuable hoards (rooms 9, 11, 13, 14, 19, 25, 28a, and 40), so that's about 6,000 sp-value for each hoard. In the spirit of random generation, I'll go with (10d20)x10+5000 sp-value for each, rounding off to the nearest 50.
One last note before I get to the descriptions: I'm using the notations from Lamentations of the Flame Princess for disease details. Thinking of that reminded me of the insect focus in their adventure Better Than Any Man. I haven't looked at the details of BTAM while going through this design series, but taking a quick look over its FATAL & Friends thread showed some similarities. Termite mounds are hardly anyone's intellectual property, I arrived at the idea of masses of minor insects interrupting resting of my own accord (inspired by Hollow Knight, as mentioned before), and I won't look at BTAM's details before finishing this series, but I won't deny that I have read BTAM before and may have been influenced by it subconsciously. Take that as you will.
Also, I'm sure BTAM is a better adventure overall if you want something insect-themed, so if you must choose one between it and my final product here, I'd recommend going with BTAM.
On to the rooms!
1: Minor ramp from entrance up to chamber. Thick smell from rotting dismembered animal remains. 3 soldiers guard exit to 2 and choke point to 3.
8: Minor ramp from entrance up to chamber. Strong moldy smell from 8a. 2 soldiers, 1 guarding each choke point from intruders, 1-in-4 chance for 1d6 workers.
8a: Tubular white fungus on moldy bed of leaves and cottony mycelium. If eaten, save vs. death to avoid iron poisoning (incubation 6 hours; duration 5 days of nausea, gut pain, bloody vomit; interval 12 hours of -1d3 Constitution, fever, dizziness, short breath, seizures).
9: Piles of mangled corroding bronze, brass, iron, and steel. Noisy searching has 50% chance to find 2d10+40 sp of salvage (1 stone each) per PC-turn searching, max. total 5700 sp. If searched, 1-in-6 chance to require save vs. death to avoid tetanus (incubation 4 days; duration 4 days of facial and abdominal muscle spasms, stiffness, headaches, fever; interval 6 hours of -1 Strength and Dexterity, fever, short breath, back spasms).
11: Intact trophy room with stone walls. Cabinet with 3 bottles of wine (115 sp each) and bottle holding 5 doses of potions of healing, stone bust (400 sp, 5 stone) on marble pedestal (200 sp, 15 stone; 4800 sp, 9 stone slug of gold sealed inside bottom), wall of 10 mounted animal heads (10 sp, 2 stone each), display case with pyrite trophy (worthless, 1 stone).
13: Floor sloped towards southeast. 13 brass statues (150 sp, 12 stone each), 7 bronze sculptures (200 sp, 10 stone each), and platinum chandelier (1700 sp, 20 stone) with 100 azurite embedded (10 sp each).
14: Countless varieties of fungi, growing around 2 shriekers and tended by 2d6 infected workers. Very humid and warm. Secret door to 15 has relief of a soldier's head. If collected and/or consumed:
1 - Coral
2 - Cup
3 - Mushroom
4 - Puffball
5 - Sheet
6 - Tube
1 - Red
2 - Yellow
3 - Green
4 - Blue
5 - Purple
6 - White
7 - Black
8 - Brown
1 - Crippling sense of fear! -2 to all attacks and saves for 2d6 turns.
2 - Throat swells! Save vs. death or take 1d6 damage/round for 1d6 rounds from suffocating.
3 - Beyond an allergic reaction! Save vs. stone or petrify for 2d4 weeks.
4 - Gravity lightens! Doubled carrying capacity for 1d12 hours.
5 - Lucky hallucinations! +2 to all attacks and saves for 3d6 rounds.
6 - Oily discharge from skin! Immune to grapples/restraints for 2d20 rounds.
7 - Toxins induce chronic vertigo! Lose 1d4 from Dexterity permanently.
8 - Draw death's gaze! Lose 1d4 from hit point maximum permanently.
9 - Achieve enlightenment! Understand all spoken languages for 1d6 hours.
10 - Break out in noxious sweat! The scent enrages termites, lasts 1d6 days (can wash off with alcohol).
Each type can be collected 1d6 times. Each sample is worth 40 sp.
15: Mummified soldier head behind wall from 14 blocks doorway to stone building. Moving it releases toxic gas, -3d6 Constitution in 20 ft. radius for 1 round (save vs. death to reduce to -1d6). Room is empty aside from splattered soldier body remains.
16: Bare stone room, 10 ft. ceiling, ghostly glowing blue runes writhe on walls. West wall ripples like water. Stepping into it teleports to a random room (roll 2d20 for room, 1d6 for orientation).
17: Soft purple glow from ceiling opening. No insects within 5 ft. of it. Constant downdraft carries a sweet smell. 1-in-10 chance sundew has extended a leaf through the opening.
19: Entrance slopes down from 20. Black and white petal-shaped fungus growing around yellow puffballs on beds of dead giant termites, tended by 1d6 workers. If eaten, save vs. death to avoid lead poisoning (incubation 2 days; duration 7 days of joint pain, headaches, short temper; interval 1 days of -1d3 Intelligence, vomiting, mood swings, infertility/miscarriage). Glints of metal in the fertilizer. Searching releases 10 ft. cloud of spores (save vs. death or -1d3 Charisma from facial swelling) and 30% chance to yield 1d100 sp in platinum shavings, max. total 6200 sp.
21: Scraps of fungi from 19 litter the floor. Both entrances slope up from choke points guarded by 1 soldier each. Additional 1d4 soldiers and 1d6 workers in chamber.
25: Marks from climbing gear near entrance, ascending from ground. 10 ft. ceiling, slope down from entrance, glittering crystals in walls. Full of pallid, child-sized toadstools among ankle-deep organic sludge. Smells of decaying meat and stagnant air, requires save vs. death each turn to avoid -1d6 Constitution. Rotting body surrounded by 3 violet fungi in east wing has grappling hook, 9 iron pitons, two watertight leather scroll cases (Light and ESP), and a waterlogged book (worthless). Sludge yields 2d20+80 sp of rough gemstones per PC-turn searching, max. total 6050 sp.
26: Blacklight from glowing mucus of sundew north of shaft, hordes of scorpions milling on walls and ceiling. Smells like sugary pastries. 1-in-4 chance of faerie.
28a: Dry air, 10 ft. ceiling, smells of kelp and prickly pears, motionless scorpion hordes on ceiling. Ornate oak table (3000 sp, 24 stone), too large to fit through choke points unless quartered (pieces of 600 sp, 6 stone each), value drops by 50 sp per turn in termite areas. Hollow shaped-wood statue of Daughter of Four Seasons in each southern corner (1500 sp, 10 stone each), value drops by 100 sp per turn in termite areas. 2-in-4 chance of faerie.
29: Poster bed of bamboo stalks, woven reed canopy, and warm sand "mattress". Dry air, perpetual smell of spicy incense and sea salt. Sleeping in bed causes nightmares of endless falling through whispers (save vs. spell, success: 1 question of Commune as dreaming insight, failure: -1d6 Intelligence and Wisdom). 1-in-4 chance of faerie. Sleeping with him doubles effect of bed for 1d4+8 hours after sex, grants immunity to poison for 1d6-1 hours, causes total colorblindness for 1d4-1 days, and requires save vs. death to avoid impregnation (regardless of PC's sex).
34: Acrid garlicky smell, eye irritation. Small garden of black cup fungi growing on visible veins of pyrite, tended by 1d4 workers. If eaten, save vs. death to gain enhanced vision (+1 to all attacks, +2 to saves vs. visible effects and illusions, lasts 2d12 hours, non-cumulative).
35: Entrance from 32 is choke point blocked on inside by corpses of 7 workers (open doors check per PC-turn to remove each). Still, dry air, desiccated remains of countless fungi litter floor. If collected, use table from room 14 for form/color, 1d4 samples per type worth 4 sp each. If eaten, save vs. death to avoid 1d6 turns of cramps and vomiting.
37: Slope up from 36, choke point guarded by 1 infected worker. 3 infected workers in chamber guard entrance to shaft. Soft sounds of dripping water and constant updraft of clammy air from below.
40: Piles and piles of mangled and corroded grey metal. If searched, 1-in-6 chance to require save vs. death to avoid tetanus (incubation 4 days; duration 4 days of facial and abdominal muscle spasms, stiffness, headaches; interval 6 hours of -1 Strength and Dexterity, fever, short breath, back spasms). 50% chance searching yields 2d100 sp of platinum and titanium scraps (1 stone each) per PC-turn, max. total 6200 sp.
41: Bare room, very humid, walls glisten with moisture, dripping water sounds from north. North exit choke point guarded by 1d6+2 infected soldiers, west choke point guarded by 1 infected soldier, east exit guarded by 2 infected soldiers.
43: Condensation drips from above. Northern half has nursery with dozens of eggs tended by 1d6 infected workers. Southern half is brackish water pool connected to underground reservoir, very minor current. If drank, it's quite refreshing, but no special effects.
44: Termite king, termite queen, 3d4 infected workers, and 1d4 infected soldiers. Dozens of eggs and immature termite nymphs. Shine of clean grey metal from west, dripping water sounds from south.
44a: Rough mound of lead and tin scraps. If searched, 1-in-6 chance to require save vs. death to avoid tetanus (incubation 4 days; duration 4 days of facial and abdominal muscle spasms, stiffness, headaches; interval 6 hours of -1 Strength and Dexterity, fever, short breath, back spasms). 10% chance searching yields the hive caller per PC-turn.
Note that I caught a numbering error with the first underground level's map (no room 36), so see the updated version below:
Well, that's actually about half of the dungeon keyed already, which is more than I would tend to do upfront, but I suppose I was rather inspired for this one. This has gone on for a while, though, so I think this is a good place to stop for now. Next time, I'll put together the NPC stat lines and random encounter lists (I still need to decide if I want separate lists per level or a stepped table), and I'll also review what sort of rooms I've keyed already to decide how I want to approach random generation for the rest. I think one more part after that should finish things off: keying the rest of the rooms, settling on mechanics for the magic items, pulling diseases into a single reference block, pulling monsters out of the room keys to put into a roster, touching up the maps to have proper text/symbols instead of freehand scribbles, and compiling everything into a (hopefully) 2 or 3 page key plus 1 page appendix.