We suggest you register your game account in case that you change your device or reset your device operating system. If you do lose your account, we will help you to get it back once we confirm the following information you supply: Nickname in game, which Kingdom, Gold amount, whether you have purchased in game and Purchase order, recently purchased items, battle details and so on. We need to check the data that others don't know. If you cannot supply the above information we are sorry that we couldn't help you.