The new schooling-leaving age policy in New South Wales, a state in Australia, requires all students to stay at school until they are 17 years old. The policy was introduced in January 2010, with little warning and, it appears, little consideration of its impact in complex contexts. In south-western Sydney, the most diverse region in the city, the impact is just being felt. In this paper, we draw on Ball's approach to policy, maintaining "the complexity and scope of policy analysis--from an interest in the workings of the state to a concern with contexts of practice and the distributional outcomes of policy". The paper explores the impact of the increase in school-leaving age on the curriculum, and the implications for ethnically diverse schools, and for students with learning and behavioural issues. Interviews with principals, teachers, parents and students suggest that there are dimensions of gender, ethnicity and ability to consider when responding to the new policy. Many schools find a lack of opportunity or too much competition for opportunities, and limited pathways. Whole school change is restricted by inadequate resourcing in some schools and by insufficient social networks in their communities. (Contains 1 note.)