This thesis critically analyzes the fundamental mechanics of the medieval fantasy genre, including its relationship with violence, environment, worldbuilding, and power dynamics. This thesis aims to help establish the start of a lexicon of shared terminology and fantasy novum to better facilitate criticism of medieval fantasy as a distinct genre. Fantasy, Tolkien, and science fiction scholars, amongst others, feature in this thesis to elucidate the current scholarly conversations surrounding fantasy. Said authors also help to illustrate the two primary, fundamental forces of medieval fantasy that this thesis posits are key to understanding the genre for the sake of further critical analysis and improvement of the craft. The two terms are of the authors’ own creation: Culture and Commerce. Both terms are defined and explored in depth in this work. This thesis, furthermore, demonstrates Culture and Commerce in action by integrating a narrative structure to demonstrate how medieval fantasy writers in the past have used Culture and Commerce and how today’s writers may use an understanding of those fundamental fantasy forces to evolve their craft.