Sunday, 8 April 2018

Cavern Generator, Part 1: Underground water, flooding, lakes and rivers.

Here is a basic cavern map generator, designed for when the party bashes through the dungeon wall and finds them selves subsumed within the larger underworld/stumbles across a cave opening in the overworld. 


Further, here is a list of d8 types of cavern that will lead to a further d40 table to generate what type of cavern has been mapped using the table above.

Cavern types, d8:


1.     Underground water, flooding, lakes and rivers.
2.     Abandoned underground dweller architecture
3.     Underground vegetation
4.     Minerals and rocks
5.     Mud, death, blood
6.     Underground humanoid habitation
7.     Underground animal habitation  
8.     Underground weirdness


1) Underground water, flooding, lakes and rivers

1
2
3
4
1
Soft, soothing drizzle leaks from the ceiling in a constant rain.
Perfectly square cut geometric canals, feet wide, turns the dry components of the cavern into a maze of walkways.   
Pools of clear water, illuminated from below by glowing multicoloured ores and minerals.
Large still pools, fungal lily pads floating atop surface.
2
Damp, vaguely muddy, recently drained or emptied cavern lake bed.
Shimmering curtains of water flow in sheets from the ceiling.  
Some hidden wind tunnel billows water from leaking roof, an underground squall.
Steady leaks pour through ceiling like heavy rain.  
3
Small puddles, dripped slowly from the ceiling.
A large pool of perfectly translucent, crystal clear water.  
Incredibly high moisture content in the air, everything dripping but seemingly no source.   
A slightly green hued pool, drinking the water has the mildest of restorative effects.
4
Cavern lake employed for a very long time as a wishing well. Filled with bizarre coins and baubles.
Cavern is a waste high pool, filled with surging, throbbing, brain like coral.
A red and black ichor choked pool filled with corpses of local fauna.
Iridescent shimmering pools that give perfect reflections of those that peer in. Sometimes the reflections act differently to those being reflected.  
5
A nigh perfectly circular ring of water rims the cavern, the center of which has become an island.
Crushingly powerful waterfalls erupt from the ceiling. They will pummel and pulverise those caught in its torrent.  
White steaming pools/lakes, roll a d4:
1) Slightly stings skin, but miraculously removes all dirt/stench.
2) Will melt flesh but perfectly clean metals.
3) No physical effects but removes magic effects from person.
4) No physical effects but removes magic effects from item.
Glooping and bubbling field of quicksand like sinking mud.
6
White translucent vines and ferns explode about the edges of several clear pools.
The visage of some enormous beast or monster is crudely carved into the rocks, the maw of which is a waterfall or lake.  
A clear fresh pool surrounded by a grove of spongy, fungi ferns. A collection of the less monstrous local fauna lap peacefully at the pool.
Rock is mutated and warped into a biological looking mass of fountains, natural spouts and pools. At times appears to breath.
7
Bubbling, steaming and salty thermal pools.  
A deep dark lake, in which some cyclopean ruins dwell. Great, ill formed pillars peak above the water line.
Swirling whirlpool, greedily pulling those that enter it deeper down into the underworld.
A small, somewhat hidden pool, fed by a stream that flows backwards from some crevice. Drinking it gives visions of the future in dreams the next time the drinker sleeps.
8
A deep, dark lake, The shore is slimy with muck and filth. Something foul lurks at the bottom of the water.
A lake so huge and wide it could be considered an underground sea.
The water in this cavern is glue like and viscous, whether it is slowly sludging down the walls or sitting still in a pool, pudding like.
The stone is a porous limestone. Flooding is rotting the stone and it is falling apart in deep fissures and pits.
9
A stream or river that plunges over the side of a bottomless pit or cliff in a thunderous waterfall.
Boulders, small and larger, rumble and splash downstream from somewhere higher in the cavern complex, linked by stream or river.
A Lake or pools in this cavern are covered with thick layer of craggy scum that give the appearance of other rock in the cavern, camouflaging the water.
The cavern houses some ancient aqueduct system, overflowing and decrepit, of some long dead underground civilisation.
10
Some deep electrical current surges through the water of the cavern pool or lake, causing damage to those that enter it. It glows faintly blue.
Ancient moss and mould covered cyclopean stones have dammed up the cavern stream entering the cavern. One exit out of the cavern is the now dry water course.
The water of the cavern pool/stream/lake/river is fouled with some ink like substance. It runs black and stains all it touches.
A poisoned, diseased pool. Dead rotting bodies of local fauna surround body of water. Drinking either causes instant death, a disease, or long endured poisoning.


Some wet cavern inspiration images: 







If needed here is a generic stocking table for filling those caverns with additional things:

d4 d12
1
2
3
4
1
Empty, place of rest.  
Empty, place of recreation.
Empty, place of physical work.
Empty, place of physical storage.
2
Empty, place of sleep.
Empty, place of ornamentation.
Empty, place of ritual and worship.
Empty, place of waste disposal
3
Empty, place of eating.
Empty, place of lavatory.
Empty, place of mental work and research.
Empty, place of mental storage
4
Empty, place of bathing.
Empty, place of mechanics and machinery.
Empty, place of growing.
Empty, place of secrets.
5
Foe, sleeping or resting.
Foe, conducting relaxation or recreation.
Foe, physically toiling.
Foe, hidden and watching.
6
Foe, eating or drinking.
Foe, indisposed through sickness or misadventure.
Foe, conducting ritual or worship.
Foe, mentally toiling.
7
Foe, ignoring treasure.
Foe, indulging in treasure.
Foe, transporting or protecting treasure.  
Foe, searching for known of treasure.
8
Treasure, subsumed in location.
Treasure, out of place and unusual.
Treasure, focus of work or worship.
Treasure, hidden.
9
Trap, natural hazard inherent in environment.
Trap, set by nearby foes, evidence of their work.  
Trap, obvious and menacing.
Trap, hidden and deadly.
10
Foe, trapped in natural hazard of environment
Foe, using traps to their advantage against interlopers.
Foe, vaguely aware of trap, but not knowledgeable of specifics.
Foe, unaware of trap they may be about to trigger.
11
Device specific and inherent to environment, expected but intriguing.  
Device external and unusual to environment, out of place sourced from elsewhere.  
Device used in regular work of environment, mundane but effective.  
Device with obscure, secret use that belies a shadow use of environment.
12
Foe, using device to conduct relatively mundane activity.
Foe, puzzling over the way in which a device is used.
Foe, using device effectively to halt interlopers.
Foe, using device for a dark, devious and deviant purpose.