A method for controlling access to deprecated methods of an implementation is provided. The playing field comprises a plurality of rooms, doors, roof hatches, and lights. For example, when a user operates an icon on the screen, the change data density of the differential region corresponding to the icon becomes larger than the change data density of the differential region corresponding to the background portion of a video image. Creation of the second replica is suppressed unless the first replica becomes invalid so that storage space is conserved without substantially increasing the risk of loss of information represented by the object. In some implementations, movable layers of the array can be disposed between at least a portion of the plurality of driver lines and stationary electrodes of the display.