Academic outcomes of post-16 education can be understood in terms of their value for gaining access to university and, at a time when global educational mobility is growing, internationally recognised university entrance qualifications may be considered a form of personal capital. However, narrowly measured outcomes may not reflect the breadth of the school experience nor the extent to which this breadth contributes to the development of the young person. One curriculum which aims to prepare students in ways that extend beyond the academic is the International Baccalaureate Diploma Programme, which incorporates an experiential element at its core. Creativity, Activity, Service attaches a transformative purpose to education, where students' experiences in each of the three strands can support personal learning that is not confined to subject areas of an academic curriculum. This paper describes the evolution of CAS in the academically rigorous Diploma Programme and presents the findings from a review of literature which contribute towards developing an understanding of the transformative potential of this component.