I distinguish four different interpretations of ‘equality of opportunity.’ We get four interpretations because a neglected ambiguity in ‘opportunity’ intersects a well-known ambiguity in ‘equality.’ The neglected ambiguity holds between substantive and non-substantive conceptions of ‘opportunity’ and the well-known ambiguity holds between comparative and non-comparative conceptions of ‘equality.’ Among other things, distinguishing these four interpretations reveals how misleading ‘equal opportunity for advantage’ formulations of luck egalitarianism can be. These formulations are misleading in so far as they obscure the difference between two separate claims about which inequalities are consistent with true equality. Luck egalitarianism claims that inequalities that have been chosen in some suitable sense are consistent with true equality, while the traditional ideal of equality of opportunity only claims that inevitable inequalities that have been determined through fair competitions are consistent with true equality. Obscuring the difference between these two claims therefore serves both to arrogate the rhetorical advantages of the traditional ideal to luck egalitarianism and to cover over a limitation to luck egalitarianism’s ambition to provide a comprehensive principle of distributive justice.