We had a game tonight. I'm running the Charnel Crypt (which is very fun by the way). It has pretty much everything I like in an adventure. Anyway, I looked at the errr...beastie therein, from which the module derives its namesake, and thought to myself "My gosh, a 10 hit die creature. This is going to be a party massacre." Well, it wasn't. In two rounds it was dead! The berserker did 43(?) damage to it in one turn (a critical and lots of damage). I couldn't believe it. I double-checked the damage was legit, and it was. It got a few good hits in, but a lucky petrification save was made, so no one died. I honestly expected quite a different outcome.
Moral of the story? The dice will always surprise you.