To successfully use God of War 3 save game files on your PlayStation 3, you must correctly format your USB drive and "resign" the files so they match your console's profile. 1. Where to Find Save Files
On the PS3, all game progress is stored in the system storage. You can access it through the home menu: Go to Game > Saved Data Utility (PS3™). Highlight the God of War III save file. Press Triangle and select Copy. Ps3 God Of War 3 Save Game Files
How to use these files: You must use a tool to change the save file's Account ID and Console ID to match your own. To successfully use God of War 3 save
or similar) containing actual game progress, such as Kratos' health, magic levels, weapon upgrades, and current checkpoint. Global Settings/Profile "PS3 God of War 3 save game files