From the introduction: The World of Gaia is the original and presumably the default campaign setting for the Engines & Empires steampunk fantasy role-playing game. This first section serves as an introduction to the setting and an overview of the book, which is admittedly limited in scope — like so many RPG supplements that purport to describe a campaign “world”, this one really only details a single sub-continent, called Arcadia, which is in many ways a perfectly typical “fantasy Europe analogue” — but with one major exception. Instead of the standard medieval fantasy milieu, Arcadia is well into its Age of Steam (with the overall vibe being somewhere between Napoleonic and Victorian).