Most often found on stage or movie/television sets, trap doors can be motorized or manually operated. If manually operated, they are typically counterweighted for easy lifting.
Trap doors can be used in multiple ways including providing actors and performers access to upper parts of the stage or set in a non-visible manner, concealing characters as they make their entrances and exits so they do not disturb the flow of the performance, and creating unexpected moments for an audience.
Trap doors are popular in magic and illusion acts as they can make performers appear or disappear in an instant, creating a moment of surprise and wonder.