This chapter argues that of all the aspects of time-consciousness, experiential succession is not only of paramount importance, but also nomologically necessary for experience. The chapter specifically argues in favor of a “Succession Requirement” for agentive subjects. This requirement states that, in order to be an agentive subject, a being must have successive experiences, regardless of whether it has insight into its own phenomenology. The chapter argues for this conclusion by considering that non-successive experiencers (NSEs) are impossible in the kind of world we live in. There are three main reasons for their impossibility: (1) non-successive experiencers fail to stand in the right sort of causal relationship to the outcomes of their actions, (2) they exhibit the wrong sort of epistemic status for agency, and (3) they lack the requisite agentive mental attitude of intentionality. I then suggest that, probably, the succession requirement can be extended as a precondition for the existence of a minimal, subjective self. Along the way the chapter also discusses implications not only for our understanding of time-consciousness, but also for free will and the philosophy of action, ethics, Buddhist and Christian theology, metaphysics, epistemology, and science fiction.