This chapter unpacks the implied meanings of the concept of ‘vulnerability’, and how they evolve depending on the conceptual frameworks in which ‘vulnerability’ is used and mobilised. It tracks down and confronts the various functions that ‘vulnerability’ has received in the academic literature and in EU asylum law, in view of identifying its conceptual transformations as it travels across the ethical, heuristic, and legal and bureaucratic frameworks. Based on that analysis, the chapter warns against the ‘humanitarianism trap’, that is, developing ‘vulnerability’ as a tool for asylum and migration governance while adopting an excessively emotional and moralised outlook on migration movements, which essentialises migrants seeking protection as passive victims, fails to build on their coping and resistance strategies, and ultimately loses track of their rights.