As I understand it, the setting of Golarion and Cheliax is Lintamande’s take on the world from the Pathfinder RPG system. She’d already written lots of glowfic stories in that setting by the time Planecrash came to be. Meanwhile, Eliezer had already written about dath ilan in some other places (like the original April Fool’s post, and later on in some shorter glowfic threads). So there was definitely lots of pre-existing worldbuilding.
But whenever the story demands it, the world is further fleshed out. Eliezer even occasionally posts Twitter questions on things like “what’s the best way to do X” as inspiration for dath ilan’s Civilization.
As I understand it, the setting of Golarion and Cheliax is Lintamande’s take on the world from the Pathfinder RPG system. She’d already written lots of glowfic stories in that setting by the time Planecrash came to be. Meanwhile, Eliezer had already written about dath ilan in some other places (like the original April Fool’s post, and later on in some shorter glowfic threads). So there was definitely lots of pre-existing worldbuilding.
But whenever the story demands it, the world is further fleshed out. Eliezer even occasionally posts Twitter questions on things like “what’s the best way to do X” as inspiration for dath ilan’s Civilization.