The world, or at least the material plane, is on the inside of a vast, hollow sphere. In the center lies a single great sun, with 8 great shafts of obsidian transfixing it. These shafts occasionally shift, creating seasons. No one knows what is on the other side of the sphere. No one has ever dug all the way through it. However, occasionally, when people dig deep enough, they find another cavern like their own. Or perhaps not. Perhaps, it is similar, but the material plane is from long ago or from the future.
There are many other planes. There is a great wheel of planes representing various alignments, with various races inhabiting it. Mirroring the material plane are the Plane of Fey, Shadow. Ethereal, and Dreams. Two other important planes are the Astral Sea, where many gods have realms, and the Elemental Chaos. The elemental Chaos was once many planes, each a different alignment, but they now mix freely. However, there one will find more air than anything else where the plane of air once was, and what was once the plane of negative energy still drains life.
Various trickster gods are chief gods, as they are the only ones most of the other gods can agree on. They limit influence in the material plane simply to make things more interesting. Inera, Loki, Hermes ,and Lildall are the four most powerful. Coyote is currently attempting to edge out Loki
These are the greatest of the non-chief gods, but are effectively greater gods
Sublimity-Through-Patience: Is the sun itself. An ancient deity, he retains a demeanour foreign to those of the current epoch, using a description in place of a proper name. STP is beyond a doubt, nearly unstoppable as a god as nearly all creatures have need of the sun and the life it brings. Despite this, STP maintains a hands-off approach to the world, having few lesser aspects in the world. The few he does maintain are inconspicuous and are usually difficult to identify as STP. Gods of justice, life, civilisation and order flock to his banner, though rarely does he aid them. When he does however, victory is almost always assured. If the Titan idea is pursued: STP is the Titan of Order who survived by editing his own soul. If chaos magic idea is pursued: several of those binding spirits are STP probing lifeforms on ihow to act 'godly'. His inactivity is partly due to his knowledge-probing and because he's also making sure none of the other Titans ever find out. The other half is that he genuinely likes his current role in the universe. If trickster god idea is pursued: STP answers all direct prayers with his godly incandescence. All petitioners have some learnt not to praise the sun. Instead, they praise his team of secretaries. Lesser gods and heroes are also regularly summoned by these secretaries to go on a quest with failure resulting in a redemption quest to fight the Titans.
Selene: an outcast amongs the great gods due to her youth, having ascended into greater godhood just before the last ice age and as such is still remembered as a mortal by her peers. Formerly being the ruler of a vast elven empire, her ascension resulted in the utter extinction of all pure elves, leaving only aberrants and other genetic oddities. In modern times, Selene takes the form of a giant spherical satellite that orbits the world, called the Moon. Before her ascendence, the world in fact did not have a moon. As a deity, she presides over the night, wisdom and knowledge. She is at significant odds with the other great gods due to her continued studies on the metaphysics of the world, especially godhood. This has resulted in a glut of weak-but-numerous gods under her command. If trickster god idea is pursued: Selene often raises random anythings to godhood for varying amounts of time. For purely scientific reasons, of course.
Selene blocks half of the sun, rotating around, creating a night effect
Magic is something utterly alien, seeping through cracks in the hollow world.
It is possible to bind spirits to oneself. This enables a less alien form of magic, but can have backlashes