Definition
To use the same methods that someone else uses, especially in order to gain an advantage over them.
He's good at spreading rumors, so we decided to play him at his own game and let him experience being hurt by rumors.
This company always uses unfair business practices to defeat its competitors, but now we will play them at their own game.
Politicians often attack each other in debates, so he shouldn't be surprised when his opponent plays him at his own game.