https://4gameforum.com/showthread.php?t=13923
every dagger stab is a critical hit...
now that you can skill crit, it's different story.
it has always been 2x damage on those.
the bonus u mention should be added to the normal non critical stabb...
so you should stab for e.g 1000 damage non buffed and for more damage when u add all those crit damage bonuses... buffs, epics etc.. which makes lets say 1700 damage...
than the skill crit will always be x2..
http://boards.lineage2.com/showthread.php?t=236201