So once you have the perks which allow you to pacify enemies, what factors into whether that succeeds or fails?

I assumed higher charisma would help, but it doesn't seem to.

Luck?

The value of the weapon you're point at them maybe?

How close you are to them?

I'm interested in playing through using this mechanic extensively, but I'd really like to know how best to optimize it.

I just recently picked it up (not much else I ~need~ at level 85) but I have not used it yet. I assumed that the ~only~ factor was whether you were higher level than the foe or not. Without the Awareness PER perk (which may not do what I think it does), I figured I'd just look for the skull icon next to a foe's name. Of course at level 85, I doubt there is ANYTHING higher level than me in the game world, now.

It MIGHT have something to do with distance and/or gunpower. In Dying Light, you can point a gun at human thugs and they will put up their arms but (I learned the hard way) if you move your gun OFF them they will run away and/or seek cover and look for a way to attack Not sure if Fallout-4's Intimidation lasts a certain amount of time and then wears off, or what.

Luck seems to in my personal experience, I don't have any hard data to back it up though.

I dont think there are any formulas, or ones that are known yet. I always assumed it was charisma. I run a melee build but I keep a revolver handy for the pacify, it's not upgraded and I dont have the gunslinger perks, but I still have about a 50/50 chance, so I dont there are many factors. Once pacified, it doesn't wear off unless you accidentally hit them in combat, you pacify a second target, or you reload a save.

It feels like a 33% chance or something thereabouts, at 10 charisma and 3 levels of intimidation perk. That said, the 2nd and 3rd ranks of lady killer (or black widow on a female character) noticeably increase the chances of success against humans of the opposite six. My current character succeeds more often than not thanks to those.