Non-lethal attack was there from day one. Initially it was an activable low damage attack, so players would need to bring characters HP low and the finish them with that strike to knock them unconcious (I liked it more that way - at least it made an act of not killing unique). Later on (when they split jump and disengage into desperate skills) disengage took un-lethal’s spot on UI, and non-lethal attack became part of the reaction UI - honestly that UI was so small in those days and would cut off most of reactions so non-lethal’s existence could easy be missed. For some patches now non-lethal was hidden under passives, and really, one has little reason to visit that window.
Unfortunately, so far it feels like a mechanic they implemented but forgot about. I have seen no progress made on it. Except for few specific interactions it is not recognisable as a thing.
