There's no one-size-fits-all answer to this question, as the best way to outsmart someone who plays mind games depends on the specific situation and the person you're dealing with. However, there are some general tips you can keep in mind that may help you come out on top in a battle of wits with a manipulative individual.
First, try to stay calm and collected when dealing with someone who is playing mind games. This can be difficult, but it's important not to let your emotions get the better of you. If you show that you're frazzled or upset, they will only use it against you. Instead, remain cool and levelheaded, even if they are trying to goad you into losing your temper.
Second, don't hesitate to call them out on their behavior. Mind games are often used as a way to control or dominate others, so standing up to them can be an effective way of putting an end to the game playing. Point out what they're doing and why it isn't fair or helpful - most likely they'll back down when confronted directly like this.
Finally, try your best to avoid getting sucked into their game altogether. If possible, walk away from the situation or simply refuse to engage in whatever it is they're trying to get you do. This can be easier said than done, but it's important not to give them the satisfaction of knowing that they've gotten under your skin.
All in all, remember that there's no surefire way to beat someone at their own game - but by remaining calm and collected and refusing to play along, you'll at least have a fighting chance.