  John Rawls’ work explains why the concept of luck has had a central place in discussions of justice over the last 30 years. In an immensely influential section of his A Theory of Justice he introduced the metaphors of the social and natural lotteries (for a brief overview over Rawls’ appeal to luck and the legacy of this appeal, see Knight and Stemplowska 2011, 2–9). The underlying idea is that every person’s starting point in society is the outcome of a social lottery (the political, social, and economic circumstances into which each person is born) and a natural lottery (the biological potentials each person is born with). Rawls says that the outcome of each of person’s social and natural lottery is, like the outcomes of ordinary lotteries, a matter of good or bad “fortune” or “luck” (Rawls 1971, 74, 75).  Hence, since one cannot possibly merit, or deserve, an outcome of this kind, people’s starting positions cannot be justified by appeal to merit or desert (Rawls 1971, 7, 104). It can be seen, then, that Rawls’ social and natural lotteries provide negative support of his theory of justice. They undermine alternative theories in which distributions of social and economic benefits deviating from that prescribed by the difference principle are tolerated (Nozick 1974, 216; Arneson 2001, 76). They also underpin Rawls’ claim that a system of natural liberty—one in which formal equality of opportunity obtains in that “all have at least the same legal rights to all advantaged social positions” (Rawls 1971, 72) and applicants are assessed on their merits alone—is unjust because “it permits distributive shares to be improperly influenced by” the outcomes of the social and natural lottery.