Wizard with a Shotgun (Guns in OD&D)

Every now and then I read a post somewhere and it sparks. It's as if just the right words were dipped into the subconcious and come back, but changed. Reading this laudation for D&D over at Dungeon of Signs reminded me of an, for me at least,  unsolved problem (how to handle gun damage in D&D) and inspired this post (so, thanks for that!).

Here is what happened (an example)

A wizard finds a strange artifact. Basically it's a handle with two short barrels and two triggers. His superior intellect tells him something will happen if he pulls the triggers (the dwarf agrees). He aims at the fighter  and (using both triggers) rolls an 18. His normal damage roll (as we play it) would be 1d4 per barrel (any other system maybe 1d6 by default for every gun?) and rolls a 3 and a 1. He rolls a 2 on the d8, hitting the right leg. The leg goes splat and disappears in a red mist! Everybody is surprised...

Damage by class, but...

In our game we use a damage by class system* and it works very well as an abstract damage system for all weapons you might expect in a fantasy setting. Not so much for guns, though. Guns are far more deadly and need less mastery than a sword or an axe. I always wanted to have a fast and easy approach for this, ideally something that isn't too much effort to memorize. Now, here is what I came up with (it should work with all damage systems).

Fast and easy gun damage for every D&D game

Treat every hit as if it was an attempt to hit a random location of the body (1d8: 1 left leg 2 right leg 3 left arm 4 right arm 5,6,7 torso 8 head) and add every result over the number needed to hit the target (under normal circumstances) to the damage. Use this house rule for aimed hits and dismemberment to determine the result:

3 x hd (or level) + ac-value (take it all, magic, dex, protection, whatever)

= damage needed to dismember or cripple

Wizard with a shotgun (resolution)

Found at memecenter.

A wizard (Level 5) finds a strange artifact. Basically it's a handle with two short barrels and two triggers (sawed off shotgun, +6 due to scattering). His superior intellect tells him something will happen if he pulls the triggers (the dwarf agrees). He aims at the fighter (level 4, AC 3 and 34 hp) and (using both triggers) rolls an 18 (+6 for scattering, +1 for DEX, 25 all in all). The wizard needs at least a 14 to hit AC 3, so he has 11 points more. His normal damage roll (as we play it) would be 1d4 (any other system maybe 1d6 by default for every gun?) and rolls a 3 and a 1, resulting in a total damage of 26 (two times 11 because double barrel, plus 3 and 1). He rolls a 2 on the d8, hitting the right leg (the fighter's leg withstands 18 (3 x 4 hd + 6) points of damage. The leg goes splat and disappears in a red mist (the fighter looses the leg, but gets only 18 points of damage, he will bleed for 8 points of damage in as many rounds if nobody helps him, resulting in the full 26 points of damage)! Everybody is surprised...

A game of numbers

So defining weapons is just giving them a base damage (something like 1d6 for all of them) and the rest is easy regulated by giving them bonuses (like the shotgun) or penalties (a derringer, for instance). It's more damage on higher level without depending on weapon mastery or skill and could impress a dragon.

*Basically the hit die and you get more dice of the same when you would get another level in weapon mastery meaning more attacks or better aiming, etc.).