Oerik Underdark

The Underdark is a vast and largely unexplored subterranean realm that stretches beneath the continents of Oerik (home to the Flanaess) and Faerûn. Though separated by culture, cosmology, and pantheon, the Underdarks of both worlds share certain truths: they are labyrinthine, alien, and merciless.

These subterranean depths teem with ancient civilizations, bizarre ecosystems, and maddening dangers. The Underdark is not a single cavern system but a layered world, descending through miles of rock into stranger and more hostile realms.

The Underdark beneath Oerik and Faerûn is not just a network of caves—it is an entire dark mirror of the surface world. Civilizations flourish in gloom, monsters rule forgotten thrones, and ancient secrets lie buried in black stone. Whether exploring the Vault of the Drow or descending into the depths beneath Skullport, adventurers find that the Underdark does not forgive weakness—and seldom grants second chances.

The Underdark beneath Oerik and Faerûn is not just a network of caves—it is an entire dark mirror of the surface world. Civilizations flourish in gloom, monsters rule forgotten thrones, and ancient secrets lie buried in black stone. Whether exploring the Vault of the Drow or descending into the depths beneath Skullport, adventurers find that the Underdark does not forgive weakness—and seldom grants second chances.

Geography

The Underdark is typically divided into three depths:

  1. Upperdark – 0 to 3 miles below the surface. Close enough to the surface for occasional trade, raids, or escape, the Upperdark contains the most contact with surface dwellers. Caverns here may serve as hiding places for outcasts or as secret lairs for monsters.
  2. Middledark – 3 to 10 miles deep. Home to entire civilizations cut off from the surface for millennia, this layer is a realm of advanced magic, treacherous alliances, and alien logic. Travel becomes more dangerous as food, light, and breathable air grow scarce.
  3. Lowerdark – 10+ miles deep. The true abyss of the world. Here, reality begins to twist. Ancient powers slumber in forgotten cities, and even the stone seems to whisper. It is a place of Elder Evils, godlike entities, and forgotten things better left undisturbed.

The Underdark is not well-charted but no less terrifying. Known locally as the Deepearth, it supports entire civilizations that have never seen the light of day:

  • Erelhei-Cinlu – The decadent drow city beneath the Vault of the Drow, capital of the drow realm of Zirnakaynin, deep under the Hellfurnaces. The drow here serve Lolth and rival demon lords in eternal intrigue.
  • Aboleth enclaves and illithid colonies operate beneath regions like the Sea of Dust, Hepmonaland, and the Crystalmists, influencing surface events through sleeper agents and psychic manipulation.
  • Dwarves and deep gnomes (svirfneblin) hold scattered strongholds in the Cairn Hills and Abbor-Alz, constantly beset by underdark horrors.
  • The Elder Elemental Eye, tied to the cults of Elemental Evil, is whispered to have roots in the Underdark depths beneath the Temple of Elemental Evil and beyond.

The Lost Caverns of Tsojcanth, Maure Castle, and Castle Greyhawk all contain portals or shafts that descend into deep, unnatural tunnels—some leading to ancient realms of pre-human origin.

Localized Phenomena

  • Magic can behave erratically in some regions, especially near faerzress (a raw magical radiation unique to the Underdark of Faerûn).
  • Portals, ancient glyphs, and long-lost teleportation circles allow for strange shortcuts—and deadly traps.
  • Travel is slow and often vertical. Rivers, fungi groves, and chasms can be landmarks or deadly hazards.

Fauna & Flora

  • Drow (Dark Elves) – Matriarchal, cruel, and cunning. The most infamous Underdark denizens.
  • Duergar (Gray Dwarves) – Grim slaveholders and smiths twisted by illithid cruelty.
  • Illithids (Mind Flayers) – Psychic tyrants with alien motives, dreaming of the return of their ancient empire.
  • Aboleths – Immortal, aberrant entities older than the gods.
  • Beholders, cloakers, myconids, deep dragons, and many unique monstrosities.
  • Demon Lords – Creatures such as Demogorgon, Orcus, and Lolth have walked the Underdark, leaving chaos in their wake.

Type
Underground / Subterranean
Location under

Comments

Please Login in order to comment!