A Zapper Light Gun is a pistol-shaped electronic device sold as part of an original NES system. It allowed players to aim at the TV and, depending on the game, shoot pixelated ducks, clay pigeons, gangsters, terrorists, and many other obvious targets. It worked by changing the light content of a frame on the TV when a trigger was pulled and bouncing an infrared signal off of the screen. If the signal matched a certain wavelength, modified by the picture, a "hit" was scored, otherwise, a "miss". A game had to be specifically made to use the Zapper, and several of these are considered the most addicting games ever made. Many are the stories of a hard core enthusiast spending six hours attempting to earn a million points on Duck Hunt.
