The Underdark Caverns of the Most Bizarre and Dangerous

Written by Loremaster Aemon

The Underdark, Where the Strong eat the Weak, and The Stronger eat the Strong.
-The wise words of an Underdark explorer

The Underdark

The Underdark is a subterranean world of the unknown. Mostly a lightless world, except for the florescent fungi and plant life you may find. Full of intrigue and Danger, the hunter can easily become the hunted, not everything is as it first seems.

The Underdark Geography

• Caverns: Natural and man-made, from a few feet in diameter to hundreds or thousands of feet wide and deep.
• Tunnels: Man-made and Natural tunnels are everywhere throughout the Underdark.
• Huge Caverns: You may think a cavern a few hundred feet wide is huge, what if you found one miles wide??
• Deep Gorges & Steep Climbs: Before you know it, your standing on the very edge of a deep gorge, looking down you see nothing but darkness. You drop a copper piece, to see how deep it goes, you don’t hear it land, you have no idea.
• Mines: Many Humanoid races build mines for the resources that the Underdark generates, from coal, oil, stone and Ores, to salt, fresh water, precious gems and fungi (only found beneath the surface). Humans and Dwarves are the most common of the races to build and work mines. The Drow, Orcs, Dragons, Illithids and some Human Nations like Thracia and Zamoria have their mines worked solely by Slaves or Prisoners.
• Ruins & Sunken Ruins: Deep beneath the surface are many old ruins above and below water. It has been recorded that explorers have even found Ancient ruins of extinct civilizations.
• Tombs: Be on your guard when opening a stone portal, what lies beyond could be a Mummy Lords Burial chamber or a Crazed Wizards lair where he finally achieved Immortality as a Lich.
• Temples: Ancient Temples of forgotten or Dead Deities (Vestiges) are often unearthed in the Underdark.
• Cities: Many races have built Cities or Kingdoms in the Underdark, the most common being Dwarves, Drow, Duergar and Deep Gnomes.
• Settlements: Settlements are small and usually built near a resource that is crucial to the economy or survival of the race.
• Outposts: The Drow and Duergar typically build outposts to gather troops, preparing for a raid.
• Strongholds: Only Dwarves and Duergar build Strongholds, usually as the first line of defence for a City or Kingdom.
• Dungeons: An Adventurer or Explorer can easily stumble upon the Underdark when exploring the dungeons of a castle, as a found secret passage, or escape route leads deeper underground than they first thought.
• Rivers: Most Rivers of the world start their journey from beneath the surface, and some rivers only flow throughout the Underdark.
• Waterfalls: You can find many waterfalls throughout the Underdark, made when a river or stream cascades over the edge of a fissure, rift or canyon creating these beautiful water features.
• Water-Filled Caverns & Tunnels: You can find water-filled caverns or tunnels, which are created when a river overflows and has no where else to go.
• Lakes: Lakes form underground just as they do on the surface, though not many will be as cold as a Deep Lake.
• Ice Caverns: Like the Ice lakes, extreme cold locations have caverns of ice, created naturally by the elements or hollowed out by creatures or Humanoids.
• Ice Lakes: In extremely cold subterranean locations lakes of ice can form. Some recorded Ice Lakes have filled caverns hundreds of feet in diameter.
• Fungus & Molds: Some of the most poisonous Molds and Fungi grow only in this strange environment. Some races grow and harvest certain fungi as a main source of food.
• Traps: Always be on the lookout for something out of the ordinary, It could be a trap set by an intelligent creature. Do you really want to be a Troglodytes next meal!!!.
• Blocked & Collapsed Tunnels: It is easy for a tunnel to become blocked. It could be on purpose to keep out unwanted intruders or an earth tremor caused the ceiling to collapse.
• Fungus Forests: Throughout the Underdark there are many Fungus filled caverns. A race called Myconids live in and cultivate all types of fungus. It is believed, somewhere in the Underdark is a cavern so huge, tens of miles wide overgrown with a Forest of Fungus.
• Lava Flows & Lakes: Deep in the Lowerdark you can find lakes of burning lava, sometimes connected by rivers of lava (lava flows). Exploring such places could find you accidentally entering The Elemental Plane of Fire.
• Active Kossutha (Volcanoes): Be extra careful if the tunnel or cavern ahead seems to be rising in temperature, or if you see smoke or steam ahead. You could be heading towards a vent in the worlds core, A Kossutha, the smoke could be poisonous gases escaping.

Standard Creatures (Fauna) of The Underdark

• Bats And A Swarm of Bats,
• Carrion Crawler,
• Crab,
• Darkmantle,
• Firenewt Warrior And Firenewt Warlock of Imix,
• Fungi,
• Giant Bat,
• Giant Centipede,
• Giant Constrictor Snake,
• Giant Crab,
• Giant Fire Beetle,
• Giant Poisonous Snake,
• Giant Spider,
• Giant Rat,
• Grell,
• Grimlock,
• Magmin,
• Meenlock,
• Mephits,
• Myconids,
• Oozes,
• Piercer,
• Quaggoth,
• Rat And A Swarm of Rats,
• Roper,
• Rust Monster,
• Shrieker,
• Stirge, and
• Violet Fungus.

lava Caves & Waterfall Cavern by jbrown67

The Uderdark,Bizarre & Dangerous by oldschoolroleplaying

Type

Underground / Subterranean

• The Upperdark: upto 1 mile below the surface
• The Middledark: 1 to 5 miles below the surface
• The Lowerdark 5 miles or more below the surface

The Drow, Their Minions and Their Creations

• Draegloth (Drow Creation),
• Drider, and
• The Drow.

A Drow Cavern City by Dandwiki

Tribal Races of The Underdark

• Azer,
• Bugbear,
• Bullywug,
• Deep Gnome,
• Derro,
• Duergar,
• Goblinoids,
• Hobgoblin,
• Kobolds,
• Kuo-Toa,
• Orcs,
• The Dwarven Race, and
• Troglodyte.

The Most Dangerous Creatures of The Underdark

• Aboleth,
• Ankheg,
• Beholder,
• Cave Fisher,
• Dragons,
• Giants of The Ordning,
• Hook Horror,
• Illithid,
• Otyugh,
• Purple Worm,
• Umber Hulk, and
• Xorn.

An Underdark City by ebonfort Wikia