The system makes sense in theory.
The current implementation is shit.
One of the examples is the kid thiefling dying due to snake bite. You either get lucky on a roll or she dies. It's retarded. Keep the dice roll if you want in order for me to maybe convince the bitch to not be evil to the child, but if that fails, then at least let me carry through with my intentions. If I could not save the kid by talking the bitch down, then let me intervene and fight them to protect her.
This is just one example of course, there are lots of other interactions such as this throughout the game where the player gets locked out of options due to RNG. It's poorly done. Failure could be interesting sure, but it's not in this game.