Language invention has occupied many brilliant minds throughout history, from the philosophically driven pursuit for the prelapsarian “perfect language” of Adam in the Middle Ages (Eco, 1995) to the more utilitarian 20th-century aim of facilitating communication in an increasingly globalized world by creating languages such as Esperanto and its offspring (see Okrent, 2009). At the same time, language play and language invention seem to be as much of a common human activity as is the building of imaginary worlds. In fact, one field where the two often meet naturally and effortlessly is the case of childhood paracosms (see “Worlds as Paracosms” in this volume).