Underdark

Geography

The Underdark's underground landscape varies from small subterranean fissures almost impossible for adventurers to crawl through, to wide expanses of deep water that hide coral caves, hollowed out sections of ice in which creatures live, and places where fungus, bones, or even pure force form "caves." This varied landscape is as dynamic as the Prime Material Plane. Some areas were always changing over time because of underground magma rivers or the emptying of underground lakes due to cracks in the rock formed by earthquakes. This meant maps of the Underdark were highly unreliable. The Underdark is not a single, continuous cavern system, and even places on the same level may not connect to each other. The existence of Underdark settlements beneath Tinkertown and Anthor, for example, does not mean it is possible to travel from one city to the other underground. In fact, the Underdark consists of a number of discrete domains. A domain is simply a collection of Underdark locales among which underground travel is reasonably easy. In certain places it may be possible to trail-blaze a route from one domain to another, but then again, it may not. An Underdark domain is something like a large island in the surface world. It may feature several distinct terrains and cultures, but it's possible to travel all over the island without having to set sail on the ocean. Similarly, two locales in a single domain are connected by enough cave systems, tunnels, and other passages to enable travel from one to the other without leaving the Underdark. Cities and settlements in the same domain are much more likely to engage in diplomacy, trade, or warfare than cities in separate domains. Like the continents or regions of the surface world, domains tend to group disparate cultures together and force them to interact with each other for good or ill. Terra Caelum's Underdark consists of seven major domains, a dozen or so minor ones, and hundreds of otherwise isolated locales that don't appear to connect (at least not easily) to any other Underdark networks.

Type

Dimensional plane

Included Locations