1. improve your performance in something
you must step up your game if you want to succeed/keep your job
To 'step up your game' means to improve the way you play or to improve so that you can perform as well as others. When you 'step up your game' you make an effort to be better in the way that you do something. This expression is usually associated with sport or work performance. "We will have to step up our game if we want to have a chance of winning the championships."