Equal opportunity, also called equality of opportunity, in political theory is the idea that people ought to be able to compete on equal terms, or on a “level playing field,” for advantaged offices and positions. Proponents of equal opportunity believe that the principle is compatible with, and indeed may justify, inequalities of outcome of some sort. . .The ideal of equal opportunity does not necessarily lead to equality of outcome since its aim is consistent with allowing people’s life prospects to be influenced by their values and choices. From that standpoint, the underlying motivation of the ideal of equal opportunity, properly understood, is to counteract the effects of people’s different natural and social circumstances while permitting inequalities of condition that emerge as a result of their choices. On that basis, some scholars have argued that inequalities arising from differences in choice are not only just but necessary, to give personal responsibility its due. That view is sometimes described as luck egalitarianism.Luck egalitarianism maintains that, while inequalities are unjust if they derive from differences in people’s circumstances—because circumstances are a matter of brute luck—they are just if they are the product of people’s voluntary choices. Luck egalitarianism is thus a combination of two different claims: first, that justice requires the neutralization of the effects of differences in people’s circumstances, and, second, that it is just to require people to bear the costs, or allow them to enjoy the benefits, of their voluntary choices. In making those claims, luck egalitarianism invokes a distinction between choice and circumstance, or between brute luck and “option luck.”Luck egalitarianism has its critics, however. Given the social forces to which each person is subject, the distinction between choice and circumstance, or between brute luck and option luck, is not always easy to draw in a plausible way. But even if a satisfactory way of drawing those distinctions could be found, there is still the worry that luck egalitarianism is too harsh in the way that it holds people responsible for their foolish or reckless behaviour. It seems to imply that those who end up needy as a result of their own imprudence can justly be forced to bear the costs of their choices. So, people who choose to smoke with full knowledge of the risks involved and develop lung cancer may have no entitlement to the health care that they need but cannot afford. Uncompromising luck egalitarians may insist that they have no objection to voluntary schemes to help those with self-inflicted needs but that they regard the forcible extraction of taxes to help those who are responsible for their plight as sanctioning the exploitation of the prudent. Others, however, may concede that luck egalitarianism should be supplemented with a further principle of justice, such as, for example, a principle holding that the needy—that is, those whose condition falls below some threshold—are entitled to support regardless of how their needs arose.