Are you talking about patenting a gameplay idea? They aren’t very effective, basically impossible to enforce, and aren’t going to completely stop being ripped off. Also completely original gameplay ideas are rare these days.
Copyright automatically applies to anything you make in the US even if it’s unpublished. If someone is ripping off your characters, music, etc, it’s pretty straight forward making a copyright claim. But remember that other people are allowed to have things that look very similar to yours without it being copyright infringement.