Once you open a Chest, you will get Rumbler units that will help you upgrade your Rumblers. To do so, go to “My Team”: if any of your Rumblers has a green bar and arrow, then it means an upgrade is available. Click on it and select “Upgrade”.

Enjoy your powered up Rumbler!

Maximum levels for each Rumbler type are the following:

Core - Level 25

Pro - Level 21

Superstar - Level 9

Legend - Level 5

NOTE: As the upgrade costs gold, make sure you need that upgrade before confirming it, as we will not be able to reverse it and refund its cost.