In the years 1918, 1919, and 1920, the Berlin Dada movement, mounting less than thirty productions, exerted a formidable, if indirect, influence over the development of the German theatre. This influence would later lead to the dismantling of Expressionism as the dominant theatrical force in Central Europe. Retooling the theories and performance techniques that they inherited from the Futurists and the Zurich Dadas to their own specifications, the Berlin Dadas introduced the use of pure—onomatopoetic or vowel—sound and abstract movement, improvisation, simultaneous and illogical actions, verbal and physical assault on the spectator, antiillusionist scenic design, and the incorporation of popular entertainments, such as cabaret acts and cinema, into German performance.