All stories take place within a fictionalized world that differs, be it in large ways or small, from our own. Even stories based on actual events feature invented characters and scenarios that are created during the process of converting history into narrative. Some stories depict worlds that are very similar to our own but feature a few noteworthy changes, such as a version of our world in which superheroes exist or an exploration of how history would have been different if the Soviet Union had won the space race. Still other stories take place in completely invented places, such as Westeros in Game of Thrones or Adventure Time’s Land of Ooo. In this chapter, we will step away from Bitsy for a moment to present a systematic approach to worldbuilding, from defining the fundamental principles governing our new story’s setting to fleshing out the languages and cultures of its inhabitants.