How are the worlds of videogames designed, organized, and navigated? What guides players through these environments, and what underlying principles shape those experiences? From the ancient towers of Elden Ring to the suburban housing of The Sims 4, real architectural theory is put into practice across twelve iconic games, with detailed sequences of plans, maps, sectional views, 3D renderings, and exploded diagrams exposing the foundational structures that govern gameplay. This landmark study of digital space-making reveals how these worlds are built to be an integral part of the player's experience.