Commitment to the ‘rules-based order’ (RBO) has emerged as a leading discourse among advocates for stability in global order. Yet, despite the most authoritative rules being those agreed between States to be legally binding, it is primarily political voices that advocate in these terms, often assuming that they also embody lawyers’ commitment to the ‘international rule of law’. Legal scholarship has in contrast remained sceptical regarding both the meanings of the RBO and the perils of uniting legal and non-legal rules within a single normative ideal. This paper defines the RBO in jurisprudential terms in order to interrogate a core strategic assumption driving the discourse: that establishing accessible and pragmatic non-legal rules that are consistent with international law, complements and reinforces legal rules governing the same subject matter. Using the case of the proposed ASEAN-China Code of Conduct in the South China Sea (COC), the paper demonstrates that the RBO and the international rule of law are antagonistic normative ideals in cases where legal rules have failed to constrain the competitive ambitions of a geopolitically dominant state. In such cases, a lack of distinction between legal and non-legal rules tends to reinforce underlying power imbalances and facilitate interpretations detrimental to the integrity of law. States must instead look beyond substituting one category of rules for another and seek strategies for reconfiguring power itself. Expanding recognition of the ‘Indo-Pacific’ connects the Asia-Pacific and Indian Oceans as a single geostrategic domain, which thereby takes into account considerations of the balances of power necessary for a RBO consistent with international law.