At its core, The Cardboard Kingdom is about the joy and power of imaginative and collaborative play. While nearly every chapter explores a specific thematic issue, those dominant themes always emerge through play. For the children of The Cardboard Kingdom, play is a transformative act that turns their otherwise mundane suburb into a kingdom of fantasy and adventure. It also transforms and shapes them as individuals by allowing them to experiment with their identities, work through issues, and develop problem-solving skills, and as the children learn and grow, they cultivate important social skills that will serve them well in life.

Within each child’s imaginative landscape, the power of play serves specific purposes. For example, Jack, Miguel, and Sophie all use play to explore or express parts of their identity. Jack uses the realm of play to take on the socially edgy role of the Sorceress, a persona that gives him confidence and feels more comfortable than the real-life version of himself. Likewise, Miguel samples a variety of different roles as he attempts to define his feelings for the Prince (who is represented in a film and in the person of his friend Nate, who takes on the role of the Prince during play).