New higher lethality rule inspired by GM's toolkit one.

If more successes are generated than necessary to trigger the maximum success line of an action, the action reduces the target's armour soak value by one per extra success against this attack.

Note that there is no maximum amount of extra damage related to skill level. I think that the GM's toolkit rule overvalues already very powerful skill training. This rule also attemps to address the issue of armour being maybe too protective when compared to unarmoured style. Armour still is very effective against opponents with lesser strength, but more powerful opponets have better chance to pierce through armour.

Thug said:

I like this idea a lot, but it's worth noting that one perhaps non-obvious side effect is that it devalues Actions (and other things) that already reduce soak. Things like ***** In The Armor take a big hit from this house-rule, because they not only lose their specialness (as any attack can now diminsh soak), but they also have no benefit (unlike all other actions in this system) for getting a really good roll. That's really only a problem if you have players who already have a "ignore soak" action, and far less important if the rule were in place and explained before anyone made characters.

If I were implementing this rule, I'd probably come up with some sort of compensation for ***** In The Armor, as IMHO it's the prime attack card for high-Intelligence, low-Physicals characters. (It lets them make an attack roll using Int + Observation.) If you don't compensate it, you've just cut out a major route for many supposedly "non-combat" characters to contribute in a meaningful and aggressive way to a fight. You're pushing them further into a support role (or to just flee), and I'm not sure that's what you intended.

Actually downgrade of armour soak reducing actions was my initial concern as well. However, the propabilities of rolling four or more successes are so low that for example ***** in the Armour is still as good as before for certain (high Observation or weak) characters or any character when opponent's armour soak is very high. The real problem is that for some actions like Extreme Shot or Covering Fire this rule may trigger anomalously good damage because they only have one hammer success line. But for these actions this rule does not make much sense anyway, so its easy for GM to discard those results.