The Case of the Unlucky Crit

[DRD1812]

We've all heard stories about silly GMs ruling that player's have "rolled so high they fail." I'm talking about acing a jump check and concussing yourself on a ceiling. Aside from the fact that there aren't any crits outside of combat, this sort of thing is generally frowned upon. But there is one spot where it seems to be designed into the game: nonlethal damage.

"I gently tap the guard on the head to knock him out. Crit success! 105 nonlethal damage! What do you mean he's dead?"

Do you play it RAW, where all nonlethal damage dealt to an unconscious creature is treated as lethal damage? Or do you like to rule that player intent matters, and that knocking out a low-level guard should be possible even for a very-strong barbarian?

Comic for illustrative purposes.

[CBDunkerson]

I'd let the player declare that they aren't using their full strength bonus / foregoing power attack / whatever, but if after they've nerfed their attack to whatever degree they wish to do so they still end up killing the target then them's the breaks.

Yes, intent matters... but accidents happen.

[Lady Asharah]

You *can* kill a target with just non-lethal damage.

It's not easy, you would need to do twice their hit points in damage in a single blow (assuming you are knocking someone out and not engaging in a fight that includes nonlethal damage)

Knocking someone out by hitting them on the head is incredibly dangerous in real life, you are just as likely to cause permanent brain damage as you are to knock someone unconscious.

[Gray Warden]

If your idea of "gently tapping" means using your Greatsword 2-handed with Power Attack, and you happen to crit and kill your target, then the outcome is on you.

If you really intend on sparing the target's life, then you would not use your main weapon to deal non-lethal damage: you would use a 1-handed improvised weapon (hitting the target with the pommel of the sword, for at most 1d6 + Str damage), or no weapon at all and instead go unarmed, eventually eating one AoO (you want to spare the enemy's life, not the other way around). In both cases, you'd score a crit only on a 20, and you would of course not use Power Attack. All these precautions mechanically convey the intention of not wanting to kill the target.

If the target is particularly weak, say a peasant vs a 15th level Fighter, to the point that they would die just because of the Str modifier, then the power difference is high enough for you to ace any Combat Maneuver with very low chance of failing: Disarm the target (if they have a weapon), then Trip and Grapple, finishing with a Pin.

It's too easy to nuke them with all you've got, and then complain if they die.

After all, there is a reason why this feat exists.