Subjects in the virtual reality condition played Dactyl Nightmare. In this game, two opponents stand on raised platforms called pods. Each wears a set of goggles and a belt and holds a pistol-action device to control the perception of bodily movement through space and of shooting a gun. The goggles provide visual images of the game: by turning one’s head to the left or to the right, one alter the visual images appearing through the goggles. The belt controls the direction of movement, and one pushes the top of the hand-held device to move. It is analogous to turning one’s body to face a particular direction (controlled by the belt) and then walking in that direction (controlled by pushing the top of the hand-held device). To fire the gun, one pulls the trigger.