Underdark

Summary

The Underdark is the collective name given to several large cave networks where entire ecosystems, settlements, and even small kingdoms have arisen amidst strange magic and stranger creatures. The Underdark is set apart from the shallower areas of the underground by the deep magic, called Núrangol in the Drow and Undercommon languages. This ambient magic prevents most forms of teleportation and divination. Over time, it transforms their minds and bodies over the course of months until they lack the desire or ability to live outside of the shadows.

The Four Areas

While the true extent of the Underdark is unknown to surface dwellers, it is generally understood to have four distinct regions, each completely separated from each other and accessed through their own cave networks. The four areas are listed in order of their size below:

Eastern Laivra

Nearly as large at the rest of the Underdark combined, the Laivran Underdark's largest entrances are located in Evruxia. It extends underneath the entire Exruxe range and east toward the sea, reaching as far north as the border between Cirithas and Ramanthas and as far south as Tsuvral. Aboleths, Mind Flayers, and other horrors of the Underdark are known to live in this area and occasionally make forays onto the surface. It is the best-explored portion of the Underdark by surface-dwellers, and the most significant danger it poses to adventurers are the large, often hostile Duergar, Drow, and Vathialosi kingdoms that predominate there.

Southern Rhovra

This large portion of the Underdark can only be accessed through the Mycelian Collective, a sentient fungal hivemind that spreads for hundreds of miles. There are two known entrances to the Underdark in this territory, referred to as Descent and Center by the Myconids and other sentient fungi who dominate the area, both on the surface and in the Underdark. Many of the Drow and Svirfneblin who live there also have a connection to the hivemind, either by accidental or intentional inhalation of mind-altering fungal spores.

Northern Rhovra

This portion of the Underdark can be found under and to the southwest of the Vounas Mountains. The largest known entrance is found in eastern Xepesme. Another point of ingress can be found among the ruins north of Fana, where long-dead Machines extend well into the caves below. This portion of the Underdark is more feral than that in Laivra. The Vathialosi are the predominant sentient power here, though most of this portion of the underdark is overrun with monsters.

Southern Deep

According to the Aarakocra, the Larmashi Islands have their own version of the Underdark inhabited by a fish people called the Kuo-Toa. The locals stay well away, and only a few explorers from the mainland have written accounts of this portion of the Underdark. From these short accounts of the upper layer of this portion of the Underdark, it is known that the Kuo-Toa use giant effigies to create malevolent spirits to do their bidding.

Deepfolk

While there are sentient creatures like Myconids that are native to the Underdark, the majority of its intelligent residents originally came from the surface. Elves and Gnomes are affected the most by the Núrangol, so they form a significant portion of its residents. Though Dwarves are less drastically affected, their closer proximity to the Underdark makes them more likely to be exposed. Though the nature of this magic is known to surface-dwellers and most avoid it, those fleeing war, persecution, or a life of crime may find living in the deep preferable to their fate on the surface.

Drow

The Drow are the most numerous of the Deepfolk, living across all areas of the Underdark. The Núrangol turns their hair white and their skin a dark grey to match the rocks they live among. The Drow interact more with surface-dwellers than other Deepfolk, though this interaction is as likely to involve kidnapping and slavery as it is to lead to diplomacy or trade. Though they are perfectly willing to venture outside the Underdark, they are the least forgiving of intruders. The Drow often build their settlements in areas where the Núrangol is concentrated, taking advantage of its ability to block scrying and teleportation magic. They are the best hunters in the Underdark and pride themselves on their ability to hunt or even tame the fiercest beasts below the earth.

Duergar

Dwarves are already well-accustomed to the underground. As a result, the Duergar are somewhat similar to their surface-dwelling cousins. The main differences are found in their pale eyes, prematurely white hair, and greyish skin. If they interact with surface folk, they prefer to do so with other Dwarves and may refuse to even speak to Elves, surface-dwelling or otherwise. The Duergar use their mastery of mining to significantly expand their caverns and with them the scope of their influence.

Svirfneblin

Though Gnomes are a far smaller group than Elves or Dwarves are on the surface, their numbers in the Underdark are comparable to those of the other ancestries. While most deepfolk engage in military conflict to reach for supremacy, Svirfneblin prefer a diplomatic approach. Rarely the dominant force in their local area, they thrive when they are able to play competing factions off of each other. As a result, they keep their settlements small or live in large cities built by the other ancestries. In the latter setting, many Svirfneblin work as craftsmen and petty mages.

Vathialoi

Satyrs are as capable of being warped by the Núrangol as the other ancestries listed above. However, unlike most groups who end up in the Underdark, Satyrs came willingly due to religious motivations. The deep underground is where their largest and most sacred temples to Hades, Persephone, and other underworld gods can be found, and followers of the Satyr Gods who wish to sacrifice to these chthonic deities sometimes undergo weeks-long treks in the Underdark to do so. Vathialoi have retained their culture due to regular, amicable interactions with their surface-dwelling brethren. They can generally count on kingdoms on the surface to support them in times of need, so the other Deepfolk generally steer clear of them.