Do you want to use a different Game Center account on your iPhone and iPad, perhaps to restore the progress of some games that you play? Fortunately, this is not nearly as hard as you may think, and you can do this within a matter of seconds.
Game Center uses the Apple ID that’s linked to your iPhone or iPad by default. Since Game Center accounts are tied to Apple accounts, you may have been under the notion that you cannot use a different account unless you completely sign out of your device. However, you can log out of Game Center and use a completely different Apple ID without affecting the rest of your Apple account data that are used for services like iCloud, iMessage, FaceTime, etc.