Here is my current idea if anyone could give their appreciation:
- define the dice pool as conventional dice pool definition subtracted by an extra layer of difficulty (eg. -2);
- then, if the player scores at least one success dice after the penalty, the damage they deal at the end would be total number of success dice + a damage bonus modifier (eg. +3).
This is how Chronicles of Darkness combat works. Unlike in the classic World of Darkness (20th anniversary edition and before), nothing ever changes your target number: it's always 8, 9, and 10 that count as success. Instead, increased difficulty is represented by decreasing your dice pool.
In combat, these dice pool decreases can come from your opponent's defense and generally being distracted, among other things, but also from making a called shot. But a called shot that succeeds can inflict various status effects (known as "tilts") on the opponent, such as a hit to the eyes leaving them blind, or a hit to the wrist disabling their hand. And sometimes, a called shot to a monster's weak point could increase your damage modifier: a flat number of successes added to any successful attack.
The result is that a called shot to the weak point is less likely to hit (fewer dice), but more damaging if it does (extra successes added if you roll at least one success).