The Underdark

Biomes

The underdark is vast, plunging beneath oceans and across continents. As such, there is much variance in the geography, ecology, and meteorology of the lands therein. However, several archetypical biomes tend to arise again and again due to natural pressure.

Dripping Caves

These caves are most recognizable to adventurers- carved by the flow of water, filled with underground rivers and menacing stalactites, these caves are filled with small creatures that crawl, scuttle, and flap. Some medium sized creatures will move in to take advantage of the prevalent prey, but overall these are some of the safer areas in the underdark.

Weather

1-3: Howling Gales 4-7: Misty 8-20: Calm

Travel

Due to the high verticality of the environment, traveling above a slow pace requires hourly Athletics checks. Failure causes the party's speed to drop to a crawl for the next hour. Critical Failure causes the character to gain a level of fatigue.

Encounters

1: A Black Pudding (Minor) 2: A Roper, suspended over a river or chasm (Major) 3: A party (4) of gricks in ambush. (Major) 4: A Grell Ambush (Minor) 5: A slippery crossing (Minor) 6: A blocked path (Minor) 7: A field of Shriekers (Minor) 8: A flash flood (Major) 9: A path of dead air (Major) 10: A steep descent (Major) 11: An overgrown but still recognizable corpse. 12: A large patch of ground bare of any life. 13: A migrating swarm of prey animals 14: An area of dense undergrowth 15: An area overgrown with Glowcaps, casting bright light. 16: A bloodstained patch with signs of extreme violence 17: A magnificent geolgical formation (Stalactites, Stalagmites, Crystals) 18: A grove of Hearth fruit with enough supply for 1 each. 19: A Deep Gnome: Scout, Trader, Hunter, or Exile 20: A party of traveling Myconoids: Gatherers, Traders, or Priests

Plunging Chasms

As the substructure of the underdark crumbles and shifts, great pits and crevasses carve the soil, riddled with tunnels and stone bridges that span fathomless depths. Those adventurers with a head for heights may traverse these perilous paths, but even they do so with great care.

Weather

1-3: Twisting Haze 4-7: Misty 8-20: Calm

Travel

Due to the high verticality of the environment, traveling above a slow pace requires hourly Athletics checks. Group Failure causes the party's speed to drop to a crawl for the next hour. Critical Failure causes the characters to gain a level of fatigue.

Encounters

1: A Solo Twisted Form (Minor) 2: A Party of Phase Spiders (Major) 3: A Party of Wraiths (3) and Gang of Specters (4) (Major) 4: A Gang (7) of Swoopers (Quetzalcoatlus) (Minor) 5: A Steep Ascent (Major) 6: A Planar Intrusion (Major) 7: Hostile Flora (Minor) 8: Sleeping Swarm (Minor) 9: Falling Rocks (Major) 10: The path narrows to single file 11: The darkness below glows with infernal light and the floor rumbles 12: A bridge below you swarms with danger 13: A migrating swarm of prey animals 14: A sudden warm, moist updraft laden with seeds 15: A distant tunnel colapses 16: A swarm of avian creatures fight something invisible 17: A magnificent geolgical formation (Stalactites, Stalagmites, Crystals) 18: An Out of reach Resource tempts you 19: An Unfriendly fortress 20: A Guarded Caravan bearing freshly mined ores.

Fungal Jungle

In places rich in magic, moisture, and earth, fungi thrives. If one of the three is prevalent enough, fungi can grow to unnatural sizes and fill caverns with stalks as thick as trees, shedding spores in voluminous clouds and lighting the air with bizarre bioluminescence. While some of these forests can be dangerous, whether due to poisonous spores or more active threats, others contain a multitude of rare ingredients and valuable goods, ripe for the picking.

Weather

1-2: Slimestorm 3-7: Spore Clouds 7-10: Bioluminescent Spore clouds 11-15: Fog 16-20: Clear

Encounters

• 1: Party (4) of Gas Spores (Minor)
• 2: Black Pudding (Minor)
• 2: Fungal Behemoth (Major)
• 3: Pair (2) of Ochre Jellies (Minor)
• 4: Gang (7) of Carrier Beasts (Major)
• 5: Party (5) of oozes (Major)
• 6: Party (4) of Fungal Grovetenders (Minor)
• 7: Ambush by Party (5) of Carrier Beasts (Major)
• 8: A field of Violet Fungi (Minor)
• 9: Caustic Runoff (Major)
• 10: A slick descent (Minor)
• 11: An overgrown path. (Minor)
• 12: A Pulsating Cocoon.
• 13: A Woodstalk infested with herbivorous animals
• 14: A few Nonhostile Carrier beasts
• 15: An area overgrown with Glowcaps and valuable fungi filled with bright light.
• 16: Thick tendrils of fungus spiderwebbing the ground
• 17: A gaping fisure that flexes as it inhales and exhales
• 18: A Lone injured Myconoid.
• 19: A party of traveling Myconoids: Hunters or Gatherers
• 20: A party of wary Drow gatherers.

Vast Caverns

In the Underdark, caverns can form on such a massive scale that they form their own weather systems, ecosystems, and sub biomes. One of the more dangerous areas for the unprepared, vast caverns can support super-predators far larger than could maneuver in the cramped confines of a normal cave. Despite this, most Drow cities take advantage of the wealth of resources available to settle0 here, relying on their fortifications to keep them safe. As such, the Illithid, their natural enemies will target these areas for releasing their most dangerous warbeasts.

Weather

1-2: Howling Gales 3-4: Twisting Haze 5-6: Bioluminescent Spore clouds 7-8: Fog 9-12: Rain 13-20: Clear

Encounters

• 1: A Kruthic (Major)
• 2: A Gang (8) of Darkmantles (Major)
• 2: A Gang (6) of Dire Bats (Minor)
• 3: A party (5) of Gricks in ambush (Major)
• 4: A party (3) of Red Slaad (Major)
• 5: A Mimic (Minor)
• 6: A drow puppeted by an Intellect Devourer, leading party to an ambush by a Roper (Minor)
• 7: Crumbling Terrain (Minor)
• 8: Insects that infest party's rations (Minor)
• 8: Hydrothermal Vents (Major)
• 9: Toxic Spore clouds (Minor)
• 10: A high cliff with a good view
• 11: A plunging tunnel leading into darkness
• 12: An area riddled with the dens of small animals
• 13: An outcropping of valuable minerals
• 14: A Grazer Beast
• 15: A skittish Drider
• 16: A Drow Exile
• 17: A mischievous Deep Gnome looking to play pranks
• 18: A Caravan of Deep Gnome traders.
• 19: A party of patrolling Drow Soldiers
• 20: A party of Drow hunters.

Fungal Jungle

In places rich in magic, moisture, and earth, fungi thrives. If one of the three is prevalent enough, fungi can grow to unnatural sizes and fill caverns with stalks as thick as trees, shedding spores in voluminous clouds and lighting the air with bizarre bioluminescence. While some of these forests can be dangerous, whether due to poisonous spores or more active threats, others contain a multitude of rare ingredients and valuable goods, ripe for the picking.

Weather

1-2: Slimestorm 3-7: Spore Clouds 7-10: Bioluminescent Spore clouds 11-15: Fog 16-20: Clear

Encounters

• 1: Party (4) of Gas Spores (Minor)
• 2: Black Pudding (Minor)
• 2: Fungal Behemoth (Major)
• 3: Pair (2) of Ochre Jellies (Minor)
• 4: Gang (7) of Carrier Beasts (Major)
• 5: Party (5) of oozes (Major)
• 6: Party (4) of Fungal Grovetenders (Minor)
• 7: Ambush by Party (5) of Carrier Beasts (Major)
• 8: A field of Violet Fungi (Minor)
• 9: Caustic Runoff (Major)
• 10: A slick descent (Minor)
• 11: An overgrown path. (Minor)
• 12: A Pulsating Cocoon.
• 13: A Woodstalk infested with herbivorous animals
• 14: A few Nonhostile Carrier beasts
• 15: An area overgrown with Glowcaps and valuable fungi filled with bright light.
• 16: Thick tendrils of fungus spiderwebbing the ground
• 17: A gaping fisure that flexes as it inhales and exhales
• 18: A Lone injured Myconoid.
• 19: A party of traveling Myconoids: Hunters or Gatherers
• 20: A party of wary Drow gatherers.

Vast Caverns

In the Underdark, caverns can form on such a massive scale that they form their own weather systems, ecosystems, and sub biomes. One of the more dangerous areas for the unprepared, vast caverns can support super-predators far larger than could maneuver in the cramped confines of a normal cave. Despite this, most Drow cities take advantage of the wealth of resources available to settle0 here, relying on their fortifications to keep them safe. As such, the Illithid, their natural enemies will target these areas for releasing their most dangerous warbeasts.

Weather

1-2: Howling Gales 3-4: Twisting Haze 5-6: Bioluminescent Spore clouds 7-8: Fog 9-12: Rain 13-20: Clear

Encounters

• 1: A Kruthic (Major)
• 2: A Gang (8) of Darkmantles (Major)
• 2: A Gang (6) of Dire Bats (Minor)
• 3: A party (5) of Gricks in ambush (Major)
• 4: A party (3) of Red Slaad (Major)
• 5: A Mimic (Minor)
• 6: A drow puppeted by an Intellect Devourer, leading party to an ambush by a Roper (Minor)
• 7: Crumbling Terrain (Minor)
• 8: Insects that infest party's rations (Minor)
• 8: Hydrothermal Vents (Major)
• 9: Toxic Spore clouds (Minor)
• 10: A high cliff with a good view
• 11: A plunging tunnel leading into darkness
• 12: An area riddled with the dens of small animals
• 13: An outcropping of valuable minerals
• 14: A Grazer Beast
• 15: A skittish Drider
• 16: A Drow Exile
• 17: A mischievous Deep Gnome looking to play pranks
• 18: A Caravan of Deep Gnome traders.
• 19: A party of patrolling Drow Soldiers
• 20: A party of Drow hunters.

Geography

An extensive cave system formed long ago by excavation by the Giants during their dominion. While large portions of the network have collapsed, and most others are eroded by natural forces to the point they no longer resemble artificial structures, the size and scale is too unmistakablely infeasible to be entirely natural. The collapse and shifting of various tunnels has caused the deformation of the stone into vast caverns and endless chasms; water seeps through the stone and carves underground rivers into the earth, disappearing into lightless depths. In other places the molten core of the earth has flowed upward into the caves, and while most are clear of anything more than some geothermal vents radiating heat and moisture into the air, occasional hotspots ebb and flow in a magmatic tide.

Ecosystem

Unlike the stagnant caves of the disconnected surface caves, the ecosystem of the Underdark is fueled by a constant influx of water, air, and heat, cycled and recycled through it's natural systems.

Air

The Underdark is an oppresively hot and humid place. This air constantly flows upwards through the caves which act as a natural cooling system, causing it to vent heat and sink back into the depths of the earth. The vital gasses of life stem from the waste of the various flora of the region, both plant and fungi, and is consumed and returned by the fauna that dwells around it, providing what is necessary for the flora to survive.

Water

Massive rivers wind their way through the underworld, plunging into the depths and reappearing in an unconnected cave miles away. While many of these rivers  eventually connect to the sea, enough water reaches sources of volcanic activity that reduce it to clouds of steam. This condensation eventually forms into clouds in the larger caverns, creating a weather cycle resembling the one on the surface world.

Energy

At the root of it, there are two sources of energy that populate the life cycle of the Underdark's denizens. On the mundane end of the spectrum, volcanic vents pour heat into the air, consumed by various microorganisms and megafungi to produce food. These lifeforms are then fed on by other creatures, and the cycle distributes energy in a diminishing radius around the heat sources. On the esoteric side; many of the life forms in the underdark grow too large to subsist on the predation of other creatures alone. These lifeforms exist because they have developed the ability to tap into the thaumic flows of mana that course through the once grand tunnels, providing them with the energy needed to supplement their diet.

Localized Phenomena

Rainstorms, Howling Gales, Twisting Haze Haze, Spore Clouds, Brightcap Spore Clouds, Slimestorm, Oppresive Silence

Fauna & Flora

Flora

In an environment as dangerous as the Underdark, even the plants and fungi can be dangerous. Thus, most flora is classified based on how wary you will need to be of it. Inert flora will cannot respond if not interacted with- grabbing a thorny vine will hurt, but step around it and you need not fear. Reactive flora can and will respond to environmental stimuli- step too near a Hookvine Briar, and you'd best be ready to dodge the lashing tendrils. Active flora may engage with you, rather than the other way around. Shambling mounds will chase down anything it wanders by, and a Myconoid colony may choose to begin either diplomacy or hostilities depending on their attitude towards outsiders.
Inert

Brightcaps, Creeping Jamie, Hearthfruit Shrub, Anchor Pods, Greasemold, Sallowcup, Whiteshawl, Woodstalks, 

Reactive

Shriekers, Boomfruit, Hookvine Briars, Flourcaps

Active

Myconoids, Derbishes, Walking Woods, Shambling Mounds

Fauna

Most lifeforms developed naturally in response to environmental pressures, taking sustenance from the fungi that develop around the steam of the geothermal vents and the endless rivers that form of their condensation. However, in such a high magic environment, vast numbers have adapted to the thaumic flows, wielding them in various manners to best sustain their lifecycles. Others, however, are deliberately engineered or summoned aberrations, weapons of the Illithid turned loose to breed freely and inflict maximum chaos.

Beasts

Scuttlers, M.O.U.S, Flail Snails, Darters, Bats, Rats, Grazerbeasts, Longbeasts

Monstrosities

Light-blighters, Burrowing Worms, Dark-Light Phoenixes, Lurebeasts, Ropers, Firetoads, Oozes, Gricks, Hook Horrors

Aberrations

Gas Spore, Carrion Crawlers, Chokers, Carrion Crawlers, Darkmantles, Kruthik, Mimics, Beholders

Natural Resources

The Underdark is rich in rare and highly valued species of flora and fauna, whose components can be used in a wide variety of alchemy and enchanting. While many of said species are inedible, the staple crops of Hearthfruit and flourcaps provide a solid staple to the diets of sapient species. Construction is often done of stone, but the Woodstalk Mushrooms can be dried and refined into an excellent building material. Finally, in addition to the readily available minerals distributed all throughout the crust of the world, there are also the materials which can only form due to exposure to strong thaumic fields of which the Underdark has plenty. As such Mithril, Adamantine, and Orichalcum are all prevalent throughout the area.

Type

Cave System

Related Ethnicities

• Drow

Contested By

• The Illithid Remnants
• The Silversilk Matriarchy

Inhabiting Species

• Anolian Crawler
• Indigo Wispdew
• Vivid Thoughtbane