School playgrounds are critical arenas wherein children's gender performances unfold, and 'games' of gender subordination or domination transpire. Theoretically predicated on Butlerian and Baradian gender performativity approaches, this qualitative study analyses how children negotiate and perform gender, exploring the material-discursive effects of human and non-human agents (e.g. football, sartorial elements) in their intra-actions with the body. Data were collected through observations and semi-structured interviews with 80 pupils from two Athenian elementary schools. Findings showed that playgrounds were dichotomised into rigid gender zones, and the children reaffirmed their gender allegiances by forming gender-homogeneous playgroups and engaging in diametrical activities. Gender-zone transgressions were frequent, albeit with high social and emotional cost, especially for boys who were uninterested in football and lacked athletic dexterity. Finally, the results highlighted the effects of material-discursive forces in gender identity development and, specifically, how 'successful' masculinity, girly femininity, sissies, and tomboys emerged through the material-discursive intra-actions of playgrounds, bodies, football, and heteronormative discourses.