Abstract: Focusing on early child pretend play from the perspective of developmental psychology, this article puts forward and presents evidence for two claims. First, such play constitutes an area of remarkable individual intentionality of second-order intentionality (or ‘theory of mind’): in pretence with others, young children grasp the basic intentional structure of pretending as a non-serious fictional form of action. Second, early social pretend play embodies shared or collective we-intentionality. Pretending with others is one of the ontogenetically primary instances of truly cooperative actions. And it is a, perhaps the, primordial form of cooperative action with rudimentary rule-governed, institutional structure: in joint pretence games, children are aware that objects collectively get assigned fictional status, ‘count as’ something, and that this creates a normative space of warranted moves in the game. Developmentally, pretend play might even be a cradle for institutional phenomena more generally.