This paper is a response to Sanders, Snijders and Hallsworth (2018). The challenges and opportunities of behavioural public policy Sanders, Snijders and Hallsworth discuss highlight a conundrum for the field: the impact of behavioural interventions is difficult to measure accurately in complex situations, and yet complexity is inherent in the very areas in most need of impact. Behavioural interventions will be only one tool of many to work towards broader organisational, systems and social change. As a field, we should be looking to other disciplines, inviting them into the fold of discussions on how to achieve these changes. Finally, while the mantra of nudge for good is a useful beacon, intentions are only part of the equation, and a number of questions should be asked when considering a behavioural policy intervention.