This chapter examines how maps contribute to the building, understanding, and navigation of a tabletop role-playing game world. It begins by distinguishing between a role-playing game's source world and game world, the former being materials that inform the latter. A game world develops incrementally as the group agrees on its content. The chapter then examines the case of the 13 maps in the Dungeons & Dragons adventure The Wild Beyond the Witchlight (2021), chosen because they illustrate various ways in which maps contribute to building the game world. All maps share the implicit proposition that what they show exists and are thus powerful world-building tools. By analyzing the maps in terms of “props” – actual things that generate fictional truths – they reveal varying levels of authority in relation to the game world. They range from a map with nearly complete authority over the game world, through those that argue for authority in conjunction with the adventure's verbal text, those that undermine their own authority but highlight source world possibilities for the game master, to a map designed and introduced in a way that gives it minimal world authority.