Anyone figured out what does luck / charisma affects exactly?

To me it feels like there's no noticeable difference between a 6CHA and a 18CHA toon.

@Razvan I read that it affects your rolls... so more likely to evade or block, hit for more damage etc..
Z

https://fractured.gamepedia.com/Charisma
So charisma is basically for supporters (Leadership, whatever it does) pet users and traders
Luck on other hand "biases chances"  rolls : saves (sucessfully saving against spell aka second line of saves), chance to hit / land CC (secondary line of accuracy) and damage rolls (2050 dmg weapon deals 50 dmg more often). Formula is like this:
Also natural 20 CHA increases multiplier of luck by 60%
Its weird to see no difference in survivability and offensive powers with such gap, maybe it was not fully integrated to game yet.

Hmmm, I seem to have an idea of how to create Rincewind from Discworld.

@asspirin
I am looking at the wiki and the listed calculation is this:Am I missing something or what? I made another toon with 610luck and 23% crit chance. According to the formula above,
triangle_sign = Chance  Chance * (1+ Luck/1000) = 0.23  0.23 * (1 + 610/1000) = 0.14
Biased Chance = Chance + triangle_sign = 0.23 + (0.14) = 0.09
edit:
@GorTavaro @kellewic
After a quick thought, maybe the formula is actually
this way, with my previous data,triangle_sign = 0.23  0.23 * (1  0.61) = 0.23 * ( 1  1 + 0.61) = 0.23 * 0.61 = 0.14
Biased Chance = 0.23 + 0.14 = 0.37
So basically, without taking in account other luck bonuses (from talents and items)
6CHA = 0.9x actual chance (23% > 20.7%)
19CHA = 1.225x actual chance (23% > 28.2%)
20CHA = 1.45x actual chance (23% > 33.4%)I think it's WAY MORE intuitive to show that the actual critical chance in this case is 37%, instead of showing 23% crit chance and 610 luck.

@Razvan the formula is
delta = Chance  Chance ^ (1 + Luck/1000)
might be a little hard to see it's an exponent but it is superscript to Chance.

@kellewic
Thank you! It makes much more sense now.
For anyone interested, I added a tabel of how chances scale with 100 to 1000 luck.