Do you have a certain process you always use to create a universe for a book or series, or does it all come together as you write it?
I’m not an author who can put together a “universe” on the fly, so to speak. In working on a fantasy series, the magic system always comes first, setting up the rules, not to mention the social, economic, political, technological, and military implications. Then comes the geography and political-economic setting, followed by the main characters and the problems they face.