@Oldnight,
The tricky thing in the current build is that you very often have Advantage or Disadvantage when the two creatures are not on the same height (about 10 feet ground height difference I think).
When it says 30 %, that is almost always because you are on lower ground OR the target has cover.
Also, in the core 5e rules, doing a ranged attack in melee = Disadvantage, but I do not know if BG3 integrates that now (prob. not).
Example :
Eldritch Blast with +5 to hit (so Chr 16) versus AC 16 (decent).
50 % chance of hitting. So yeah, when you playing the tabletop, you may not realize you only have 50 % chance of hitting !
With Disadvantage, the percentage is 30 %.
