This chapter maintains that the idea that there always are inherent dynamics, overlaps and osmoses between disciplines. Accordingly, it argues against holding a hard-core attitude towards interdisciplinarity as something with which to ‘discipline’ ourselves or others. Instead, it presents interdisciplinarity as an unavoidable, organic manifestation of our dynamically evolving cognition and epistemic faculties - much like language, epistemology or culture. The chapter begins with an overview of the importance of discussing interdisciplinary or its corollary ‘x-disciplinary’ methodology in context of the research methodologies of international law. It then evaluates the dual purpose of providing for scientificity and for the ‘instructions manual’ of legal research and what it requires from interdisciplinary methodology in the field of international law. Finally, it problematizes the concept of interdisciplinarity in reference to notions of trans-, bi-, multi-, anti- and post-disciplinarity. It concludes by assessing the transformative concept of x-disciplinarity.