High Quality Content by WIKIPEDIA articles! Act Utilitarianism is a utilitarian theory of ethics which states that, when faced with a choice, we must first consider the likely consequences of potential actions and, from that, choose to do what we believe will generate the most pleasure. . Act utilitarianism is opposed to rule utilitarianism, which states that the morally right action is the one that is in accordance with a moral rule whose general observance would create the most happiness. Act utilitarianism will use the summary concept as opposed to the practice concept. The summary concept means that the rule is a generalization that a class of actions, such as the keeping of promises, is good.