copycat
I played this online game https://ncase.me/trust/. The game goes like this: there are two players and you are trying to end up with more coins after all the rounds are over. Each round you have two moves you can either cooperate by giving a coin or you can cheat by not giving a coin. The opponent can make the same moves to but you both have no idea which move you will chose. If you cooperate you gain two coins each, if you cheat and they cooperate you win 3 they lose 1 and if you both cheat no one wins anything.
The best strategy in very limited one on one battles is Copycat. Essentially you start cooperative but as soon as they cheat you cheat back and if they cooperate again you follow suit. You copy what they do as the name suggests.
Copycat starts off nice but if hurt will set boundaries to punish and doesn't hold grudges. I like this because it's simple and easy to follow.
It's a cool approach that I think I will try to follow. I tend to turn the other cheek far to much and cooperate far to much.