From the introduction:
The Sundered Epoch is intended to work with most settings and Genres of games. The Genres of the Sundered Epoch exist within the setting.
The idea is that the Setting determines the availability of technology, the state of the world, and represents the environment that the Characters will live in. A Genre is a style of story. In movies, Genres are broken down in to action, drama, comedy, horror, and adult entertainment… um, er… but I digress.
Within each setting, any number of Genres are possible. For example, a game set in medieval France with magic, goblins, and dragons is a fantasy setting, but if the Characters are investigating the murder of the mayor and stumble on to a sect of religious fanatics, bent on overthrowing the local government and taking over the world… You now have a fantasy-mystery-conspiracy Genre.
Ultimately the first thing the Narrator must do is determine what the setting is. Once the Narrator has an idea of what the game world will be like, you need a plot.