A secondary world is a self-consistent fictional reality that operates according to its own internal laws, distinct from the primary world of the reader or audience. The term derives from J.R.R. Tolkien’s essay “On Fairy-Stories” (1947), where he argues that the fantasy author creates a “Secondary World which your mind can enter,” and that within it, “what he relates is ‘true’: it accords with the laws of that world.”
Brian Attebery, in Strategies of Fantasy (1992), positions the secondary world as a defining marker of the fantasy genre. Farah Mendlesohn extends this in Rhetorics of Fantasy (2008) by developing a taxonomy of how readers relate to secondary worlds—whether they enter them through a portal, inhabit them from the start, or encounter their intrusion into the primary world. Mendlesohn and Edward James, in The Cambridge Companion to Fantasy Literature (2012), consolidate this as a working definition: “Following Tolkien, we may say that fantasy is the literature of the secondary world: a self-consistent realm in which the impossible becomes normal.”
Mark J.P. Wolf’s Building Imaginary Worlds (2012) further elaborates the concept, treating literary narrative as an emergent phenomenon of the secondary world rather than the reverse—the world generates the stories, not the stories the world.
A secondary world differs from a paracosm in emphasis. The secondary world is a literary and structural concept: it describes the artifact as experienced by a reader, player, or audience. The paracosm is a psychological and phenomenological concept: it describes the creator’s relationship to the imaginative domain. A given world—such as Middle-earth, or Teraum—may be described under both terms simultaneously.
The conditions under which a secondary world maintains coherence across multiple narrations or enactments are formalized in the Reproducible Paracosm framework.