This article, which sits in the context of a wider project devoted to understanding how state behaviour may be changed, seeks to focus on the act of sanctioning, broadly construed, as functional to that goal. Freeing ourselves from the constraints of too narrow a definition of the term ‘sanction’, we consider a wider gamut of instances of penalties on target states which are intended to accomplish the goal of changing state behaviour. Our goal is threefold: first, we aim to stimulate a debate on the nature of the act of sanctioning, which, we argue, is more embedded within international law than generally conceded; second, by looking at different sanctioning practices, we aim to identify their common elements and offer a taxonomy of the act of sanctioning within international law; third, we aim to consider the implications of different sanctioning practices and, in particular, understanding how and when they can amount to effective and acceptable tools to change state behaviour.