This article claims that the protection of children’s capability for play is a central social-political goal. It provides the following three-premise argument in defense of this claim: we have strong and wide-ranging normative reasons to be concerned with clusters of social deficiency; particular fertile functionings play a key role for tackling clusters of social deficiency; and finally the capability for childhood play is a crucial, ontogenetic prerequisite for the development of those particular fertile functionings. Thus, in so far as we (...) consider it a central political goal to tackle social deficiency, we should be concerned with protection of childhood play capability. This conclusion raises new insights on the importance – for global development policy as well as for welfare states’ aim to secure social justice – of protecting children’s capability to engage in playful activities. (shrink)