For iOS:
Rumble Stars requires iOS 8.0 or later. Compatible with iPhone 4s and upwards, iPod Touch and upwards and iPad 2 & iPad mini (1st gen) and upwards.

Android:
Rumble Stars requires Android 4.0.3 and upwards. A stable Internet connection is also required in order to play the game.

Make sure that your device is connected to a steady network. Keep in mind that full Wi-Fi bars or mobile cellular data (3G/4G) do not always guarantee a good Internet connection.

A connection can become less reliable if you are playing while moving (on a bus or train, for instance), while on underground public transport, or if the network base station is too far and/or there are obstacles between the station and your device.