In theatre, blocking is the exact positioning of actors on a stage during a performance. The word comes from practices used by theatre directors of the 19th century, who worked out the staging of a scene on a model stage using wooden blocks to represent each of the actors. Today, the director usually determines blocking during rehearsal. They tell the actors where they should move for the proper dramatic and lighting effect, and to ensure that the audience can see everything.
The stage itself has been given named areas to help blocking.
- The back of the stage is considered up-stage.
- The front of the stage is down-stage.
- Stage left and right refer to the actor's left and right facing the audience. Because this is sometimes misunderstood, the terms prompt (actor's or stage left) and bastard/opposite prompt (actor's or stage right) are also used.
- House left and house right refer to how the audience sees the stage. The audience's left is called house left, and the audience's right is called house right.