Hmm, I am not sure if it was planned as an one-hit instant kill in DAoC from the very beginning, but anyway Mythic fixed that.
Perforate Artery has large bonus to damage, and combined with poisons and backstab, yes it gives infiltrators even now the possibility if specced right, kill in just couple of hits.
But, if you can in a couple of hits kill mage or other stealther type character
don't think you can do that to heavy tank, like armsman or paladin.
But, anyway, your idea is very interesting.
Thanks for saying so. The question of who or what this instant kill would work on still exists. Bosses? Dragons? Lichs? The higher up the enemies get, the more a backstab losses meaning and the ways of a warrior or mage begin to make more sense.
Like I said previously, thieves and assasins don't make good traditional heroes. They don't don magic plate mail and slay dragons. They don't summon demons and call forth lightning bolts. If this hurdle can be over come, then thieves will finally fit in single charcater RPGs. If not, then IMHO, they should stay in games like Theif and Splinter cell - games specifically designed to allow for stealth.
