Firstly, we're sorry to hear the game is crashing for you. Here are some things you can try to resolve this issue:
If you've opened a lot of apps, this can use up a lot of memory and cause crashes and general instability.
Try restarting your device and then running Realm War from a fresh boot.
If these don't help, please get in touch with us and provide us with information about:
where you're experiencing crashes.
what device and OS version you're using.
what version of Realm War you're using (please try and ensure you keep this up to date as this is often the cause for stability issues).