lightgun

A lightgun is a pointing input device that resembles a handgun and is used to interact with video games by indicating a location on the display to shoot. Traditional lightguns contain a light detector that senses light emitted from the screen when the trigger is pressed. By analyzing the timing of the detected light relative to the display’s refresh cycle, the game determines where on the screen the gun is aimed.

Most early lightguns rely on cathode ray tube (CRT) displays. The computer or console times the screen’s scan, and when the trigger is pulled the gun’s sensor detects light from the phosphors during the screen’s retrace or a brief bright frame. The system then calculates the corresponding coordinates. Some designs use a photodiode or phototransistor tied to timing circuitry; others rely on the host system’s timing signals to interpret the signal.

Variants have emerged as display technology evolved. Infrared-based guns and camera-based tracking systems have been developed to function with modern displays, often by using an external sensor or processing the camera’s input to determine where the gun is pointed. These approaches can allow lighter and more flexible accessories to work with non-CRT screens.

Compatibility and limitations are notable. Traditional lightguns typically require CRT displays to work reliably, and many do not function correctly with modern LCD, LED, or OLED screens unless specific hardware or software support is provided. Notable examples of historical lightguns include the NES Zapper, the SNES Super Scope, and the Sega Menacer, with later models for PlayStation systems.