I think u already know the question, i have 2 devices and and one game center .. My friend cant play these days , i want to help , if i log in with her gamecenter , with one device it warns me for deleting my game , plz help , i searched forums , some say the game depends on gc some says it will be deleted , is there an official answer from supercell? Its not an illegal situation .. Its like selling or giving ur device to some one ..
You need two GC accounts, log into them as you want to. It asks you to delete the other account and type "confirm" do that, and you can switch between two accounts