What Everybody Knows About the World:
In the beginning, there were two planes: the Elemental Chaos, a churning sea of matter, energy and possibility, and the Astral Sea, a plane of pure spiritual energies. From the Elemental Chaos arose the Primordials, beings of pure elements and whim who exercised their powers to create a physical reality, halfway between the Elemental Chaos and the Astral Sea. The parts of it that were too “bright” were cast away and became the Feywild, while the parts that were too “dark” became the Shadowfell. While this was going on, the Astral Sea gave rise to the gods, who descended to the Primordial’s creation (which, at that time, was much like the Elemental Chaos) and gave it stability and mortal life. Enraged by this (and probably none-too-happy about one of the gods turning the deepest part of the Elemental Chaos into the Abyss), the Primordials struck out at the Gods and thus began the Dawn War, which finally ended with the aid of the Primal Spirits (who were nominally on the Gods’ side, but mostly wanted both parties to get off their lawn, so to speak) and resulted in the Primordials being primarily slain or sealed away.
There were a number of other “little” events in the whole mess, such as Io (God of Dragons) being split down the middle by the Primordial Eruk-Hus, the King of Terror, only for his corpse to become Tiamat and Bahamut, an ambitious angel named Asmodeus murdering his god and creating the Devils, a god named Tharizdun going insane and needing to be sealed away (but not before he created the Abyss), and a few other minor catastrophes, but that’s another story.
Stone is a setting where most of the world is dangerous and places of safety are small and scattered; it is a hundred years since the human-founded empire of Andvari was torn asunder in a terrible war against a massive horde of Gnolls and their demonic allies. Monsters roam the wilderness, bandits haunt the roads, the dead do not rest easy in their graves, and wicked cults lurk in the cities. It is a world in need of heroes…