My system is a bit too involved, but I was toying around with this last year. Here’s what I came up with…
Truly D20: “Weapon Damage Ratios”
Find the size of the damage die or dice that a given weapon deals.
Divide the number of faces on the die by two, and write the result as a ratio to 6. For example, a weapon that deal 1d4 damage would be changed to a ratio of 6:2, while a weapon that dealt 1d8 would become a ratio of 6:4. Reduce all ratios; thus 6:4 becomes 3:2. This number is an attack or weapon’s “damage cycle”. A dagger has a ‘cycle of 3:1. Another way of putting it is that a dagger is a “3:1 weapon.”
The first number is called the Cycle. The second number is the Damage. When you successfully hit, determine how much damage you deal like so:
For every [Cycle] points of success, the weapon deals [Damage] Damage.
If the above doesn’t work for you or seems counterintuitive, another way to figure this out is with the formula:
[(margin of success)/Cycle] * Damage = effect (total damage)
If a hit is achieved, but not by a full cycle, the hit deals 1 point of damage.
This rule changes the role of AC to effectively reduce the severity of strikes, since higher AC means poorer strikes, and poorer strikes mean lower damage. Criticals on a natural 20 go away unless you use the “natural 20=30” rule. Some fine differentiation is lost (2d4 is equal to 1d8 once converted), but IMO, there is a net gain in verisimilitude. Fights become more personal.
When a weapon or attack deals multiple dice of damage, multiply the number of dice by the damage increment. This must be done *before* reducing the ratio.
3d6; denominator=3*3=9, 6:9= 2:3.
Code:
Conversion examples:
Dmg Damage dealt with
Die Cycle seven points of success (hit AC x by 7):
1d4=6:2=3:1 2
1d6=6:3=2:1 3
1d8=6:4=3:2 4
1d10=6:5=3:2+6:1* 5
1d12=6:6=1:1 7
*A weapon or attack can have more than one damage cycle, and each
is applied separately, and the results are added together. See below.
This is where it gets a bit complicated. Reduce all ratios to the point that they have a Cycle (the first number) of 3 or less. If a weapon cycle cannot be reduced to 3 or less, subtract the difference and put it in its own damage ratio (a weapon can have more than one ratio) and make sure to combine all fractions. For example, if a weapon ratio looks like this- 6:7, it’s not easily divisible. Convert it to two ratios of 6:5+6:2. 6:5 then splits to 3:2+6:1. Next combine the like ratios- 6:1 and 6:2, to a total of 6:3. The final ratio is 1:1. (3:2+6:1+6:2=3:2 +3:1=3:3=1:1)
When there is more than one cycle, apply each to the margin of success separately, and add the totals together. For example, with a weapon that deals 3:2+6:1 damage that hit by 7 points, the weapon would deal 4+1=5 damage.
Finally, add all weapon bonuses (to damage- bonuses to hit are added normally) in *after* determining the damage dealt by running the margin of success through the ratio. Weapon notation becomes “+5 long sword (3:2 /19-20)”.
Though the math for deriving a weapon’s ‘damage ratio’ is a bit complicated on the fly (and certainly at the table), I don’t see why a chart couldn’t be made up as a quick reference. I’d think that many people would find this too complicated, but that some people who really get into simulation of the game world would think it was worth it. This damage system is converted from a homebrew system (which was nothing like D&D) I wrote back when I left 2e. We played using it for years, and it worked fine, once you got used to it. The main benefit is that good hits=good damage.
-R. Scott Kennan
edit: had to clear up the text.