A stage that projects into the seating area and is surrounded by the audience on three sides.

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

a three-sided stage that extends into the audience and offers more audience-actor contact

a stage set at one end of the room which extends out into the audience area; audience surrounds the stage on three sides.

a stage design that allows the audience to sit around three sides of the major acting area.

A stage configuration where the audience is seated on three sides of the acting area.

In theater, a thrust stage (also known as a platform stage or open stage http://www.britannica.com/eb/article-9057183/open-stage) is one that extends into the audience on three sides and is connected to the backstage area by its up stage end. A thrust has the advantage of greater intimacy between audience and performer 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.