The proposed system comprises an auditorium, lighting facilities and a stage appearing as a container. The interior space of the container holds a liquid medium adapted for playing a theatrical performance therein, and a side transparent wall of the container serves as a stage mirror. Visual perception of each spectator is directed deep in the liquid medium through the stage mirror. The proposed stage comprises a container wherein the liquid medium is held. At least one side wall is transparent. The proposed method consists in that the stage appears as a container wherein a liquid medium is held suitable for human vital functions; at least one container wall is optically transparent, the surface of the liquid medium is isolated from the audience perception which is directed through the optically transparent wall deep in the container, and a theatrical performance is played in the liquid medium by at least one player. The proposed invention allows of enhancing the entertaining quality of a theatrical performance due to its being played in a liquid medium.