The chapter explains why the charity sector matters and, in particular, why the accumulation of assets by charities is such a weighty issue. It defines what is meant by ‘charity’ and articulates how charities form a subset of the non-profit sector. It also defines the meaning of accumulation. Having done so, the chapter articulates the questions that the book seeks to answer and the methodology adopted to do so. Those questions being: what legal constraints apply to accumulation by charities and do those constraints address the key ethical and efficiency implications raised by accumulation? To the extent that existing legal constraints do not address the key implications raised by accumulation, how could they be reformed to better address those issues?