elevator stage

elevator stage, drop stage, lift stage

A theater stage floor which moves vertically on an elevator, usually so that one set can quickly replace another; may consist of a single unit or articulated sections.
References in periodicals archive ?
We built a space in 1961 that seated 350 and had a big elevator stage that went down from first floor to basement--and up would go the new set, because you can't change sets in the round.
For the latter segment of the special, she only had 72 hours to prepare before riding into the audience's view on an elevator stage in full showgirl regalia, including a giant headdress.