I got little bored today when playing BG2 (mainly because my mods are screwed and I can't do TDD's Riativin quest and then I have no interest of reinstalling the whole game). And so I went berserk in the Temple district killing everything I could get my hands on.

I desided to try Spike Trap which I had obtained a while ago and haven't tested it yet. So I set the trap and lured a Morning Knight to it. I was astonished! Trap did kazillions of damage!
Aleina Folthen did 76 damage to Morning Knight
Aleina Folthen did 68 damage to Morning Knight
144 points of damage! Then I remembered something. Spike Trap is only supposed to do 20d6 damage! Which is max 120. Why did it do so much damage? Is it bugged or is there something I'm missing?
P.S. If it does matter, my thief's on lvl 25, IIRC.