Is it for the PC optionally the PS4 first-person shooter in which the opponents or bots have a very good AI / Battle IQ.
If yes, which.
It depends on how you define "good".
XIII (13) from 2003 (by Epic Games) has in multiplayer (bots) a good level of difficulty even on easy really appealing if you are not careful.
The bots do flanking and hiding. If you want to play the story (if it should interest you) you will also find dropouts. (I recommend Normal or Realistic.) XIII is just for the sake of creeping and VERY quick reflexes have you biting there at least 5 pistol bullets into the grass)
There's NO health regeneration in this game.
You can also die with a shot, head shots are also tried
Thanks, I forgot to mention.