Does gamestop check to see if a game works?

New games are GUARANTEED to work properly, but a used game can be different. If you buy a used game disc or cartridge, it may have a smudge or scratch that won't come off. This may limit what you can do on the game or make it completely unusable. It is hard to tell if there is something wrong with a Gameboy game, but it may have dents on the inside that can destroy the game. If the game is very old, it just might not work at all. There is the possibility that the person before you may have used cheats on the game and make it unusable. For example, I bought a Pokemon Fire red from GameStop. When I tried to access my PC, it froze. This is very rare, but it can happen. Hope this helps!! :)