Informal international public policy-making shines a light on the evolutionary flows of law under the onslaught of globalisation. The term IN-LAW, profoundly elaborated by Pauwelyn, Wessel, and Wouters, is used in contrast and opposition to ‘traditional’ international law-making. This contribution scrutinises, from an IN-LAW perspective, ASEAN and the ASEAN Community Vision 2025 as it relates to the ASEAN Economic Community (AEC) Blueprint 2025. ASEAN as an international legal person, and as grounded in the ASEAN Charter since 2008, relies on dialogue and consensus and widely on non-binding and informal regulations. Analysing ASEAN via the methodical framework of IN-LAW unveils a normative core in the fluidity of informality. This core gives a clear view of the deeper integrated nucleus of informal law. But what is the glue that binds consensus, what power does informality yield to when it comes to the substantive core of law? Therefore ASEAN will be situated in terms of its history, composition and principles regarding informality as one of its constitutive elements. Dialogue and consensus-seeking in ASEAN can be recognised as a dominant feature which, in general, fits within IN-LAW. The AEC, as one of three pillars of ASEAN Community Vision 2025, allows insights into how a blueprint can be the basis for an integrational and transformative concept for Member States. Informal processes can be detected in great variety on nearly every political level, but there are exceptions in the form of binding treaties on trade such as the forthcoming RCEP or ATIGA.