Definition & Meaning of "[beat] {sb} at {one's} own game"

What is the origin of the idiom "beat someone at their own game" and when to use it?

The idiom "beat someone at their own game" likely originated from the world of sports and competition. It embodies the idea of surpassing an opponent by using their own strategies, tactics, or skills against them. This concept may have emerged in various competitive environments, from games like chess to athletic contests. It can be used to describe instances where an individual gains an advantage by adopting the same tactics as their adversary, achieving a sense of triumph by demonstrating their ability to excel within the same parameters.