People seem to be engaging in more social action, both online and offline. A proposed theoretical model states that three key psychological factors contribute to social action engagement: moral outrage, moral self-enhancement, and participative efficacy. Moral outrage is often triggered by perceived injustice that harms a third-party victim. Moral self-enhancement involves a sense of moral superiority over other. Participative efficacy entails the belief that one’s participation will make a difference in social action. According to the theoretical model, experiencing moral outrage leads to the self-perception that one is morally superior (moral self-enhancement), which, in turn, strengthens the belief that one’s contribution to social action will ‘make a difference’ (participative efficacy). This belief subsequently increases the likelihood of social action engagement. I report several experiments that test and support the model.