This is an update of an old old post
with Midrean background
Cosmology in Midrea
Most of the details of Midrea'n cosmology are known to anyone with a decent education and at least a 14 or better Intelligence and/or any ranks in Knowledge/Religion or Knowledge/Planar. I usually assume that all PC's know these basic things just to keep things simple.
Midrea is in a pocket realm in the astral plane. It was was created about 2000 years from campaign date by an alien race called the Shapers who planned to use it as place to engage in their perpetual wars called “Strivings” without destroying themselves. This failed and the Shapers ceased to exist leaving only artifacts and ruins.
The planet is Earth sized and Earth like with s two satellites, a moon roughly the sizes of Earths and smaller asteroid. There are no other planets in the system although a star field with 13 constellations is visible.
Dotted Magic is a product of the 13 gates the Shapers used to soften space time and to allow beings to be summoned to the planet via spell. Each gate leads to a different world and someone with rare gate key or another access method can use the gate to travel to that world. In addition, certain spells can allow for planar travel though do to the nature of the world, only the gate realms are accessible.
It was thought that the elemental gates were failed attempts at Gates but later research (i.e I changed my mind) has proven this to be false.
7 of the Gates correspond to colors
#1 Red Gate.
Location: Under a giant flowstone dome in the Vinyar barrens.
Destination: Gothic-Steam-Earth This world is kind of Ravenloft meets Edgar Rice Burroughs It feature a habitable Earth, Mars, Venus and a number of exotic and dangerous technologies.
#2 Orange Gate
Location; Deep within The Chun controlled jungles near Qadesh
Destination: A decaying dying world under an sun bloated near to orange where dinosaurs have returned. Its kind of Dinotopia meets Jack Vance with a smidgen of Gene Wolfe
#3 Yellow Gate
Location: The Eye of Sand in the Stehl Mountains
Destination: Gothic Space ala 40K, the Outsider and Dune
#4 Green Gate
Location: Halfling territory
Destination: The Arboreal world forest of the Halflings
Location: Firhome at the stronghold of the Royal Academy of Magic
Destination: Something like the Earth of Call of Cthulhu.
#6 Indigo Gate
Location: Lanpon capital of the Empire of Taran
Destination; The Hall of Mirrors on The Shan home world Senn . This is a generic humans only D&D fantasy world more or less.
Location: The Elven Woods
Destination: The Elven home world commonly called Faerie
4 Gates lead to Elemental Planes
Location: Hellheart Volcano
Destination: City of Brass
Location: The Arian Trench
Destination: A cave just outside Atlantis on the Plane of Water
Location: Deepest part of the Underdark
Destination: Dead Stone Cave, Plane of Earth
Location: Bottomless pit of Tokal
Destination: Elemental Plane of Air
2 Gates lead to allegedly spiritual realms
Location: The Throne of the Gods, World Roof
Destination: Realms of the Gods of Men
Location: Hell Gate Keep, the border of the Dead Wastes
Destination: The real of the Adversaries, demons, devils, deonads, slaad
In addition there are two failed gates once in the Machine City, leading to the Machine Subrealm and another that leads directly into Astral Space which is in a contested area of the Stehl Mountain range