Many Planescape adventures take place on the Great Wheel, the Inner Planes, and the transitive planes between them. While infinite in extent, and containing similarly infinite possible demiplanes, this overlooks one of the possible attractions of the setting: the chance to adventure between one Prime and another, across a variety of interesting material worlds, some of them inhabited by their own unique and colorful cultures. Spelljammer does this in its own way, but there is, after all, plenty of opportunity for a Planescape game to walk the many Earths.
This thread is for descriptions of Prime worlds to be used as source material for adventures, backgrounds for characters, and the like. Feel free to add your own homebrew world(s), though please be considerate of users who would like to browse: capsule information should come first, and descriptions should, while evocative, be no more than a few paragraphs in length. If you have a lot of material or illustrations for your world, please feel free to provide a link to a web resource for it.
A blank template is below for people to copy and use, followed by an example.
Name:
Access:
Prevailing conditions:
Inhabitants:
Description:
Name: any known names of the world, given by the inhabitants or nicknamed by explorers.
Access: the portal from Sigil if one is known, along with its key(s) and any information such as whether access is controlled by someone. Mention that no Sigil portal is known if this is the case. Any other access information, such as commonly known spelljamming coordinates, portals from other locations, or a caster who knows the appropriate plane shift spell. Known exit routes, if access is not two-way.
Prevailing conditions: Immediate survivability requirements, environmental threats, and any planar traits of interest.
Inhabitants: Any intelligent inhabitants -- just species and density -- and the major ecology in the usual region of arrival.
Description: The longer spiel goes here. A few paragraphs on points of interest in the plane, such as why anyone would come, major geographic features of interest, more detail on any local intelligent cultures, any notable NPCs, and so on. Local adventure possibilities are highly encouraged.
Name: Psionic image from underneath sunlit water; Common name, Laguna.
Access: A two-way portal in a public bath-house in Sigil; the key is a piece of coral worth at least 50gp.
Prevailing conditions: arrival point is in water in a sheltered, tropical lagoon with shore neaby. Fresh water is nonexistent and requires magical sources, or slow desalinization.
Inhabitants: Planet's native inhabitants are a sessile, psionic sponge culture. Ecology is typical shallow-water ecosystem. A few nonnative aquatics have taken up residence.
Description: For several thousand miles around the arrival portal, Laguna is a network of shallow marine shelves and beaches, never more than a few hundred feet deep in water or a few dozen feet high at the center of the reef islands. A wide and deeper ocean beyond this is not inhabited by the locals, and little explored by outsiders who have usually arrived for resources found in the large photic zone.
Laguna is claimed by a sponge race, which developed intelligence and psionics at the dimly remembered beginning of their history, several millennia ago. The sponges have blurry individuality, being capable of combining neural networks or splitting into multiple, smaller individuals in the fashion of oozes, without apparent significant harm. The sponges vary in their psionic abilities but adults' manifester levels are a minimum of 3, and all members of the race can use far hand, sense link, and missive as psi-like abilities at will. (They may use sense link on animals, and developed their first cognizance of the world this way.) Sponge individuals may occasionally adventure in watery worlds, but are
extremely fragile bodily and require major mobility preparations. The
5th level psionic power adapt body allows a sponge individual to
survive in air and move with a perfect fly speed of 50 ft.
The typical settlement is a coral reef containing a dozen to a hundred or so individuals, though the region of the portal from Sigil has become more thickly populated. About 5% of the race possess psychic warrior levels. They rarely move -- the task requires significant teleportation or other abilities -- and care very little for material possessions, preferring to pursue intellectual studies such as the arts of psionics, magic, mathematics, and poetry and other arts. However, as outsiders have shown up and begun settling, the race has laid organized claim to the planet and constitutionalized. Settlers must now acknowledge the laws of the race's legislative body, which is primarily concerned with the conservation of natural resources.
There is very little room for land-dwellers to settle on the rare islands, which are almost entirely fed by the ocean. All of those within a fortnights' sail of the arrival portal are claimed, usually by a business or city-state that desires an embassy. Merfolk, tritons, and other aquatic sorts are more likely to settle on Laguna, underwater. Outsiders are typically interested in harvesting coral and pearl, of which the planet boasts an abundance. A single distant volcano has an obsidian outcropping, but this is more easily available on other planes.
An influx of locathah and sahuagin is leading to racial tensions, and some of the settlers who had established prospecting businesses before the sponges formalized their government are objecting to limitations on their practices. Recent stirrings from the one deep area in the settled shallow region, a long, thin crack several hundred miles south of the arrival portal, are causing uneasiness among the locals as monster attacks are becoming more frequent.