system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How the NES Zapper gun (like the one used in Duck Hunt) knew where you were pointing on the screen.
gpt
The Zapper doesn't actually "shoot" out light. Instead, it's the reverse: it's a light sensor. When you pull the trigger, the screen turns black and the targets (ducks, discs, enemies, etc.) would flash a white square. If the Zapper is pointed at a white square, it registers as a hit. This is also why it's possible to cheat by pointing at a bright light source (light bulb, window, high-brightness TV, etc.)