The classic trinity of armored fighting vehicle design is the tradeoff between Armament, Armor, and Mobility. In a practical design, all three cannot be simultaneously maximized, so engineers must determine the proper balance between these capabilities, which would offer optimal combat performance, taking into account the limitations of industrial mass production. This study explores trends in the historical evolution of combat vehicles, from their initial appearance on the battlefields of World War 1 to the modern era. Additionally, this study also examines the basic physical limitations of combat vehicle design as a whole, by presenting fundamental performance limits that are universal to all classes of combat vehicles. This analysis is used to identify key areas of research that would be of significant benefit to the development of future combat vehicles.