Some creatures in D&D 3.5 have ability drain attacks, such as the Fang Dragon's bite attack. I remember reading somewhere that for such an attack to actually 'drain' it has to deal lethal damage, implying that for non hostile situations such a creature could use it's bite attack to inflict subdual damage and not permanently damage it's opponent.
The snippet below is taken from Draconomicon to illustrate the example's ability:
Ability Drain (Su): A fang dragon does not have a breath weapon, but
its bite drains Constitution if the victim fails a Fortitude save. The
number of Constitution points drained and the saving throw DC are
given on the accompanying table.
The question is that I can't remember where I read that nor can I find it back now when looking for it. Does anyone know which particular book, rule or page covers this subject and if my 'assumption' is correct?
Best Answer
The ability drain rule says this:
Damage is never mentioned. In fact the Shadow has an attack that does no HP damage (it only does 1d6 STR damage).
It's worth noting that Damage Reduction says this:
As a non-touch attack, ability drain isn't mentioned in that list. So presumably if DR could fully stop the damage, no drain would be taken. Non-lethal damage won't stop it on its own, though.
In the case of the Fang Dragon, since the ability drain is Supernatural, perhaps it can simply not use it as part of a non-lethal attack? I don't believe that you have to turn it on if you don't want to.