In 2025, it was one hundred years since the Zöld Szamár (Green Donkey) Theatre held its first performance in Budapest, marking a century since avant-garde theatre became part of Hungarian theatrical culture. Despite this, it is still widely assumed that in Soviet and Soviet-occupied states, following the death of Konstantin Stanislavsky in 1938, experimental theatre became a forbidden theatrical practice. According to this assumption, prohibition itself functioned as the primary determinant of aesthetic decision-making, and avant-garde events emerged chiefly as communal political gestures defying censorship, with resistance serving as both catalyst and inspiration. This study seeks to complicate this view by examining two Hungarian avant-garde theatre formations: the Zöld Szamár (Green Donkey) Theatre in 1925 and the Kassák House Studio in 1973. Through an analysis of their spatial practices and the social responses they provoked, the article explores the mechanisms of cultural control operating before and during Sovietisation. The comparative presentation of these two cases makes it possible to identify avant-garde form not merely as a reaction to prohibition, but as a mode of thinking inherent in the practices of theatre-makers themselves.