What's the damage?

[Brigham]

Ok, a character says he wants to fall prone, and fails a spot check required here by the DM. He carries through with the action and falls directly on the dagger that he failed to spot. How is the damage calculated for this? Does the knife get an attack? does it act like a trap?

[FlyMolo]

Personally, just deal weapon damage.

Thrown weapons and weapons you fling at people deal regular weapon damage.

[Xefas]

I'd say the spot check was the opposed roll required to prevent damage.

So, now I think it'd automatically do 1d4 damage. Maybe +1 for the force of the fall.

[Rowanomicon]

Well if the dagger is just lying there then he takes no damage (or 1 damage if the DM feels like it).

If the Dagger was pointing up then I'd just deal weapon damage and add a bonus for the amount of force he's falling prone with. If he's totally hitting the deck and literally falling the distance then maybe like +2 or something. If he's just getting down on his stomach then no bonus, if somewhere in-between (or if in doubt) +1 should do.

Of course you can use larger damage increments then that if you like or even make it an auto-crit if it hits an organ. Or use the variable crit table (I don't know the source) to make things interesting.

[nargbop]

Oh, I once played with the nasty alternate-crit rules where three 1's or three 20's in a row meant instant death...

Although you have to ask yourself - do you want a realistic game, or a fun game? It's realistic to die if you fall on a knife in the dark. It's fun to miss the spot, get damaged, have to draw from your belly, and kill the bad guy with the knife.