Play is nearly indispensable in design for children and is often taken for granted. When designing equipment and toys with the purpose of initiating and facilitating children’s play, we rely on play as a given force that seems to be to our disposal anytime and anywhere. Being able to attract, motivate and create experiences among the players are well-known, almost obvious characteristics in play. These characteristics are, however, not well defined neither theoretically in the play research nor empirically in relation to design of products and knowledge of what attracts and maintains players in play. Substantiated knowledge about these aspects of play is in our view lacking in the play research both when it comes to fundamental research and usability-oriented research. Far from being a trivial, self-evident issue, play should be considered an independent research field which demands special attention and an independent conceptual development, which can inform design processes.