Although it is widely accepted that a theory of justice ought to be action guiding, we lack a persuasive account of what this role entails. This omission has allowed a number of misleading narratives to emerge, including the realist claim that justice is of little relevance to citizens in practice because it is not action guiding in circumstances of noncompliance. This article seeks to correct this omission in the literature by providing a general account of the action-guiding role of justice. In so doing it makes three contributions to the literature on justice. First, it explains what kind of guidance we should expect a theory of justice to offer citizens. Second, it specifies the criteria that a particular theory of justice needs to satisfy to qualify as action guiding. And third, it demonstrates that, contrary to realist criticisms, justice is action guiding in circumstances of noncompliance and so is of practical use to citizens.