Freeze
Freeze (aka Freeze tag) is a justification filler game for all players.
Anyway, two actors start a scene. Before they can get very far, an offstage actor says "freeze!" and they stop talking and hold their positions. The offstage player comes on and taps one of the actors. That actor leaves and the new one takes their place. The new actor starts a new scene, justifying whatever position the two actors happen to be in.
Actors continue shouting "freeze" and replacing each other, rarely letting a scene last more than five seconds.
Alternate version: Blind freeze
To eliminate preconceptions, actors line up, facing the wall. Two actors start a scene that none of the other players can see. Whenever it feels right, someone calls "freeze," turns around and tags and replaces an actor. The new actor starts a scene justifying the old position as it regular freeze.
Alternate version: Double blind freeze
Actors line up and two start a scene as in Double blind freeze. In this version, however, a ref calls calls "freeze," and the two players at either end of the line turn around and take the actors' places.