The Crayfish Nebula

Far out in the deep reaches of space is a region approximately 150 light-years in diameter. It is home to over 300 stars, more than 100 of which either have borne life or have been transformed to support it. The stars are colonized, organized; great Spinnergates, functional wormholes used for travel and observation, are maintained—alongside enormous space stations, an economic infrastructure on a galactic scale, and temples dedicated to studying the flow of magic—by an organization known as the Nexum.

The idyllic Nadders, the ingenious Miser Crabs, the calm Selkies, the fiery Zealots, the inscrutable Ark-Builders, the ever-mingling Morphai, the inexorable Predecessors…and plenty of smaller, less developed species, too. For example, there's that one odd biped on a small planet in a trinary system that's been causing quite a stir in recent years…

Most importantly for the purposes of the story: magic is an essential component of life in the Crayfish Nebula. But while it can be said to theoretically follow set rules, in practice magic differs greatly from one world to another. Worth simply going along for the ride, perhaps…

Because of the size of the Nebula, it is possible to view the clouds—sometimes red, sometimes gold, sometimes purple—from every inhabited world. Not quite enough to block out the stars, or the galaxy, but certainly bright enough to illuminate the night on its own accord. Civilizations across the Nebula have spun myths of Clouds Beyond the Clouds, of living heavens where the gods dwell.

They might just be right.

There are five Patron Species in the Nexum, species given the obligation of caring for their less developed kin among the stars. They are as follows:

1. The Predecessors, the first to found the Nexum after the end of the final war with the robotic Heralds. No longer corporeal, they tend to the Spinnergates in some unknowable way and manifest to other species by manipulating their memories so as to have had conversations with them.

2. The Ark-Builders, the second to join the Nexum. Having left their home planet behind long ago, these beings—which look rather like very friendly Cthulhu-spawn—create and maintain the Great Rings, special embassy worlds orbiting the Spinnergates with populations sometimes in the hundreds of millions.

3. The Morphai, the third to join the Nexum but the oldest species. Living ecosystems evolved for the high winds of a gas giant, the great sapient clouds of cells tend to the Archives, collecting knowledge and experiences from every sapient, living or dead, in the Nebula over the course of three hundred million years.

4. The Miser Crabs, the fourth to join the Nexum. Cautious, self-isolating, eager to obtain material wealth of all sorts, the large semi-vertebrates handle the Emolument Equations, without which the galactic economy could not function.

5. The Nadders, the fifth to join the Nexum. Still expanding, still learning, but eager to aid, the snake-like beings take breaks from their eternal quest for a perfect balance of pleasures to maintain the Seminaries, gathering magic-users from across the Nebula and teaching them to use their powers honourably.

Some worlds of note:

Other worlds include:

Asphodel, the cold desert homeworld of the Ghosts, a race of shapeshifters divided by colour.

Augmented Seventh Descending, the cloudy homeworld of the pre-sapient Goblins.

Babylon, a hot desert world home to the three (surviving) successor species to the Yalis—the jackal-headed Ammut, the serpentine four-armed Lamia, and the winged, flighty Peris.

France, the small, thin-aired, tundra-strewn homeworld of the Normans, a tripedal race just entering the Industrial Era.

Limitation, not actually a world at all but a vast cloud of rock and gas surrounding one star in a quaternary system, home to the Arnavajas (crystalline winged beings who reproduce by jousting).

Lux Aeterna, the homeworld of the Honorites, a wetland planet with days as long as sixteen days on Earth—and some of the most spectacular sunsets in the Nebula.

Manavi, the homeworld of the Pastors (iguanodon-like herbivores) and the Faithful (hopping marsupial carnivores), who live in careful symbiosis.

Nemus, the warm homeworld of the Arctanders. Divided into tropical desert, temperate rainforest, and polar grasslands.

Qrith, the homeworld of the schizophrenic Zealots, a race of troodon-like three-eyed beings—and once of the Groves, a forest hivemind on a planetary scale, before interstellar war destroyed them—divided into Martian summits, alpine foothills, and Cambrian lowlands.

Zirá, a planet with plants which will try to eat you and animals which inject their young into your bloodstream. Originally the homeworld of the Nepalcyons (also known as the Kingfisher Scorpions, the most aggressive herbivorous sapient the Nebula has ever seen) and the Hydras (omnivorous, not much better), now part of the Miser Crabs'.