The World Axis Cosmology is a multiverse set-up that replaced the traditional Great Wheel in Dungeons & Dragons 4th edition as part of the Points of Light campaign setting. Forsaking the sprawling, Byzantine planar mashup of the Great Wheel (which wouldn't have worked in 4E anyway with the changed to the alignment system), it goes for a simpler, more "classically fantastic" approach, boiling itself down to a few planes that adhere to distinct mythological archetypes; the mortal world, the god's world, the primordial chaos, the land of faeries and the land of the dead.
As the name suggests, the World Axis cosmology is centered around "The World" (also known as the Prime Material), with other planes being either adjacent (Feywild, Shadowfell), above (Astral Sea) or below (Elemental Chaos) - this marks "the World" as literally the Axis of the planes.
The World Axis was created when The Primordials arose in the Elemental Chaos and sought to use the barren expanse of planar space between the Chaos and the Sea as a playground, scooping up elemental matter and shaping it into the proto-realms of the Prime Material, the Feywild (from the matter that was "too bright") and the Shadowfell (from that which was "too dark"). Afterwards, the first gods descended from the Astral Sea, stabilizing the World and giving it things like life, time, seasons, and other forms of order, in contrast to the eternal flux it shared with the Elemental Chaos.
This resulted in the Dawn War, when the outraged Primordials attacked the gods for messing around in their sandbox, only to be ultimately defeated.
Fourth Edition was controversial for a number of reasons, and this was one of them. No one would argue that this cosmology is necessarily bad, even if it was a bit derivative. But it was a "change for change's sake" rather than something that came about because of burning needs on the part of the playerbase, and grognards who liked the old system hated it - especially Planescape fans, who were furious at no longer being able to consider themselves the holder of D&D's true cosmological secrets. The best ideas in it were quietly glued onto the old continuity in 5e, but much less of it survives in its present form.
|The Cosmology of the World Axis|