China's law to control international non-governmental organisations (INGOs) has sent shockwaves through international non-governmental organisations (NGOs), civil society and expert communities as the epitome of a worldwide trend of closing civic spaces. Since the Overseas NGO Management Law was enacted in January 2017, its implementation has seen mixed effects and diverging patterns of adaptation among Chinese party-state actors at the central and local levels and among domestic NGOs and INGOs. To capture the formal and informal dynamics underlying their mutual interactions in the longer term, this article employs a theory of institutional change inspired by Elinor Ostrom's distinction between rules-in-form versus rules-in-use and identifi...