Well,
how do you address it as a Christian?
So . . . for me, a mind game has meant someone just kidding, and I need to understand this. And if I see the person is short on social resources and means no harm, I might goof back at the person. I did this with one church leader, and this loosened things up. But the person seemed to have problems, doing a number of things that were mean-spirited, I would say, and not just kidding. So, I would say do not assume a person who is kidding is really a friendly person.
Another leader could make a point of joking, then observing if I was being effected. He was possibly trying to effect me so I would be charmed into accepting him and doing what he wanted.
What you mean by mind games seems to be more obviously intended to be destructive and for controlling and using people.
I think I know someone who uses various ways of talking, in order to get people confused and even afraid to say no to him; he's his own "good cop" and "bad cop". In case you mean something like this, I find it works first to be submissive to God and humble with the person. Do not try to control that person, do not try to get the person to make himself clear. Make the person do all the work, without you getting tangled with or your attention controlled by him or her.
But I be quiet and gentle, and in my prayer > in
my mind what I am communicating is > "I am ready to share, for real, if you are. But if you are trying to threaten and control me and confuse me, I am not going to cooperate, and you will have to take action and do all the work to prove what you mean by what you are saying and subtly threatening to do. And then I will not do what you say. I will not pay you money to leave me alone, because it can be used to buy drugs which could kill the children of mothers and fathers; so I am willing to die, rather than help you kill other people . . . if God makes me able to hold to this."
Once a person starts with making various statements and I don't know what he or she really means or intends, then I do not believe anything the person says, and I pray to be guided by God, what to do and say. And I do not commit to anything about the person, that I might think or suppose I should do. And keep trusting God, by the moment. And I do not give the person feedback, by making accusations or criticizing him or her; but the person is stuck with oneself > I am not a fly, and you are stuck with your own flypaper
Satan tries to play me around, with paranoid stuff. What works is I be quiet and depend on God to guide me. And Satan has to do all the work, and I do not commit to anything he is trying to get me to think or how he is trying to get me to plan how I will control a real or imagined problem person. Instead, I pray for someone who is a problem for me, and I prepare to be a good example of how to love, for the person.
And Satan is left to himself. I am not going to give him attention, and he has God resisting him, and however God has me resist him. If he tells me something, I am not going to act on it but do what God blesses me to do, without answering to whatsoever Satan brings to mind or does or threatens to do.
"Satan, you are defeated by the shed blood of Jesus," and Jesus
"did not threaten," (in 1 Peter 2:21-23) "but committed Himself to Him who judges righteously;"
So, I commit myself to God, for Him to do with me all He pleases.