The invention of imaginary worlds may be understood as a powerful tool for exploring experience, discovering the self, and creating knowledge and meaning. An imagined world is an earth or universe or a system of make-believe ideas and things that may be contemplated in the mind, though it remains veritably unexperienced. In childhood, worldplay (paracosm play) refers to imaginative pretense that is persistent, cumulative, and constructive (maps, stories, drawings, and more may be generated). In adulthood, worldplay refers to the world-building narratives of writers and artists; to the plausible reconstructions, scenarios, and probable worlds of social scientists; and to the theoretical suppositions and possible worlds of scientists. As such, worldplay presents a unique opportunity to probe what-if cognition. Indeed, as the history of its study indicates, world invention as play and as creative strategy tells us much about development of imaginative thinking and the growth of creative competence across the lifespan.

This initial chapter establishes virtual play as a historical practice, and draws its parallel with eighteenth- and nineteenth-century developments in novel fictionality. It introduces the concept of paracosmic play or worldplay – a form of modern make-believe documented in the juvenilia and biographical archives of Thomas De Quincey, Anna Jameson, Hartley Coleridge, Thomas Malkin, Charlotte Brontë, and Anthony Trollope – as the clearest manifestation of this practice. I review the social scientific work on this phenomenon, track its origins through the history of utopian fiction, and propose its formal significance and theoretical affinities to the nineteenth-century novel. This chapter frames and contextualises the historical argument of the book: that novel fiction comes of age by distinguishing the actual from the virtual.