It’s an age-old question: what exactly was going on when you laid waste to cartoon ducks with the Nintendo Zapper? The 8-Bit Guy is here to exhaustively explain exactly how this beautiful little accessory worked its magic.The answer is actually fairly simple. Obviously, the CRT monitor is a big dumb box that doesn’t provide feedback. The gun itself is also not particularly complex. It uses a lens that creates a very narrow focus for the light sensor located at the end of the barrel. When you pull the trigger, that light sensor checks to see if there is white light blasting in its direction.