You know, I've been trying to write a response to this thread for quite a while. With a name like "World Builder," I've got to have something helpful to say on this subject, right? I keep trying, but I can't come up with any general advice. I haven't found a consistent way to develop a world, each of mine have grown up in different ways.
One world began as a story. I had a story, and needed a world for it. I made a map for that story; and that map made new stories; which filled in more of the map. I refer to it as "The Big One," since its the setting that houses the majority of my fantasy stories. That's its purpose now, to house and generate stories, and the world building was done to maximize its potential. Though the magical rules are universal and definite, practical application of those rules allows for a great variety of expression. Though I've mapped most of the world, its broad and diverse enough to host all manner of ideas. Sometimes ideas for stories are generated just from the base material: at some point in history, I know the people in a certain region had a revolution and it becomes a story. Other times, the story comes of its own volition and I have to find a place for it; the story of a demonologist and his tainted daughter find a home among in a city that put aside its old religion and adopted the southern religion long ago. From those story ideas new world building details emerge.As the story is written the political, cultural, even geographic background is developed.
For another story, with the world title "Periplus of the Celestial Sea," the world building was derived rather haphazardly as ideas collided. At its core was a map of
Pangaea. It didn't look like the nondescript blob of land typically associated with the ancient super-continent. It had character and it intrigued me. I made a version of the map for myself and thought it would make a good map for a flat-earth setting. But it was a setting without a story until one day I accidentally filed the map away with some notes for a story without a setting. Or rather, a story concept. It didn't really have characters or plot yet. Just an general, overarching conflict. Some time later, I read 'A True Story,' by the Roman satiricist Lucian and some major inspiration hit me. I now had a protagonist, a setting, a conflict. I have all the immediate and universal details of the world building done, which is to say I know, generally, the main character's place of origin, some vague bits of its neighboring nations, what manner of gods rule the planets and what kinds of creatures inhabit them, and as always, how magic works.
The mechanics of magic were essential the creation of another world for a story that I'm writing with two old friends. Before we did anything else we decided that we did, in fact, want magic in this story we wanted to write, but we wanted it to be different from the magic used in any of our other, independent stories. We decided it would have some terrible, irrevocable cost. In order for a person to use magic, the magician must ritually kill another being. Death became a central theme throughout the rest of the development of the story. We determined what happens when a person dies, what sort of gods dwell in the world beyond the mortal plane, and how their motives influence the physical world. I drew up a map, but my friends refused to let me move much beyond the borders of the story. We only developed the world as necessary to develop the characters we had created. Once we knew who our characters were, what they wanted, and how they all fit together we began outlining the story and more of the world was filled in while we went. As the plot developed a city much like ancient Alexandria in terms of learning and the Vatican in terms of religious significance rose out of nothing. Mountain spirits sprung out of the rocks as needed, and artifacts of an ancient empire were uncovered. All in all we're discover the world as we plan.
So, I guess what I'm trying to say is, enough is enough. When you think you've got a solid foundation for the story you want to write, you can write it. If developments emerge in the process of discovering your world that alter the story, that's what second drafts are for. More often than not, those organic surprise discoveries are more powerful than anything you can force upon the story at initial creation. Certainly "The Big One" would be considerably weaker, more simplistic, and extremely cliche had I left it where it stood where it started. Letting the world grow on its own makes it all the more believable.
WB