What is "thrust stage"

n. a theater stage that extends out into the audience's part of a theater and has seats on three sides

In theatre, a thrust stage (also known as a platform stage or open stage) is one that extends into the audience on three sides and is connected to the backstage area by its upstage end. A thrust has the benefit of greater intimacy between performers and the audience than a proscenium, while retaining the utility of a backstage area. Entrances onto a thrust are most readily made from backstage, although some theatres provide for performers to enter through the audience using vomitory entrances. A theatre in the round, exposed on all sides to the audience, is without a backstage and relies entirely on entrances in the auditorium or from under the stage.

As with an arena, the audience in a thrust stage theatre may view the stage from three or more sides. Because the audience can view the performance from a variety of perspectives, it is usual for the blocking, props and scenery to receive thorough consideration to ensure that no perspective is blocked from view. A high backed chair, for instance, when placed stage right, could create a blind spot in the stage left action.