Final answer:
Roman theatres lacked curtains, so Romans used architectural features and stage machinery to manage scene changes and visual effects, including a well-designed backdrop called scaenaefrons, elevators, ramps, and other mechanical devices.
Step-by-step explanation:
Because there was no curtain in Roman theatres, the Romans used other architectural and mechanical methods to create visual storytelling and scene changes. The permanent facade behind the stage, known as scaenaefrons, featured multiple doors for entrances and exits, while machinery such as elevators and ramps allowed for dramatic effects and scene shifts. The Romans also included second-story windows for additional action and took advantage of the theater structure itself to create backgrounds, sometimes using wagons like the Eccyclema to reveal pre-staged tableaux or employing rotating columns known as Periaktoi.