Zero Day Piracy Protection (ZDPP) is an additional DRM check used to prevent access to the game in retail copies before the release date. It relies on an online service to decrypt encrypted critical game files stored on the retail disc, and when the user tries to launch the game the Zero Day Piracy Protection Tool is launched instead. This tool connects and transmits the ID of the protected game to Microsoft's online ZDP service hosted at https://zdp.gamesforwindows.com/Zdp/Zdp.svc/. The online service looks up the release date for the requested game ID and validates if the date have passed. If so the service will respond with the decryption codes for the protected files which the local tool will use to decrypt the encrypted files, allowing the game to be played.