During the interwar period, many artists opposed the realist/naturalist movement. Realistic art, reflecting the rules and tastes of the bourgeoisie, aimed to create an illusion for its audience. This illusion was intended to form the idea that nothing would change and that people were destined to their environment and circumstances. Bertolt Brecht was one of the most important artists who opposed the realist/naturalist movement's disconnection from life and criticized its forms of representation. Brecht developed the theory of Epic Dialectical Theatre, which bears his name, and defined his theatre as non-Aristotelian. Humanity has achieved great success in scientific and technological fields. However, according to Brecht, perspectives on progress failed to address interpersonal relationships, The rules of theatre defined by bourgeois society, was also inadequate in depicting the economic, political, and social relationships between people. Epic Theatre, on the other hand, portrays the changeability of human behavior. It demonstrates that humans are dependent on economic and political conditions and have the power to change these conditions. Thus, the audience is led to a critical judgment regarding the changeability and transformability of the world and its order. Actors in the theater, whom Brecht believed had the potential to change and transform the world, must reveal to the audience the contradictions inherent in their performances. In this context, the working method of the Epic Theatre actor is examined in light of the fundamental concepts of Epic Theatre theory. The first of these concepts, gestus, is considered the raw material, the building block of epic theatre. The concept of gestus, in acting practice, aims not only to indicate physical actions but also to make visible the social and historical relations underlying these actions. Another important concept of Epic Theatre is alienation. Events and characters are stripped of their naturalness, familiarity, and plausibility and are thus alienated in a situation that will arouse the audience's astonishment and curiosity. The two focal points of the alienation effect are historicization and dialectics.