This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University London This thesis explores the question: Why does improvisational comedy make people feel free? By drawing on psychoanalysis, in dialogue with comedy studies and Marxist political economy, the thesis surveys the structure of improvisational comedy and discovers the productive tension that exists between freedom and constraints. The thesis charts the psychoanalytic approaches to freedom in order to problematise the signifier “freedom”. It argues that the sense of freedom that improvisers, or “players”, experience in improv arises from a range of factors. Drawing on Lacanian approaches to language, the thesis argues that the indeterminacy of language and the functions of metaphor and metonymy are central to the generation of incongruous meaning and comic effects. It maintains that improv allows for making “impossible choices”, acts that set players apart from everyday life. It suggests that the retroactive fixing and refixing of meaning of signifiers creates an unusual temporality of meanings. The “event-like” structure of improv is a significant factor in allowing both players and audience to experience a measure of freedom in the improvising space. Furthermore, the thesis argues that incongruity is a motor of the comic in improv and is generated by ambiguities in language and the retroactive transformation of meanings that improv encourages. Laughter in improv is ambivalent – it can both guide and ratify the realities created by improvisors, but also mock them, or reward one over others, thus interrupting the imaginary unity of the improvising group. It further argues that the real limits of freedom in improv lie outside the improv space in the logic of capital accumulation which has commodified improv and transformed it into an industry. The thesis suggests that overcoming this limit will require lessons that can be learned from improv, in terms of making impossible choices and improvising new worlds.