Quick post because I have to get to work.
Several months ago I was wondering about how to separate deflection-type protection (shields, dexterity) from soak-type protection (armor).
In cases of uncertainty, the baseline here is the Moldvay/Mentzer Basic D&D combat system.
- Typical combat sequence is unaltered. Variable weapon damage is used.
- Attack rolls are made as usual in D&D: 1d20 + (class attack bonus/THAC0 stuff) + (ability mod) + (magic mod) + (circumstance)
- Ascending Deflection Class = 11 + (Dex mod) + (shield & shield magic mods) + (circumstance). Note: no actual “armor” in this calculation.
- If the attack roll equals or exceeds your deflection, guess what – you’re hit.
- If hit, Armor decreases the size of the damage dice: 1d10 > 1d8 > 1d6 > 1d4 > 2 > 1. Any hit does at least 1 point of damage, regardless.
- Multiple dice-types (3dX for example) shed the extra dice first, and once they hit 1dX then degrade to the lower dice type. So 2d6 > 1d6 > 1d4.
- Light armor reduces the damage die type by one step, medium armor by two steps, and heavy armor by three steps.
- Damage is then rolled “normally” – the modifed die type + (ability mod) + (magic mod) + (circumstance)
- Magical armor lightens your Encumbrance Category, e.g., a heavily laden warrior in Plate +3 moves as if totally unencumbered.
- Monsters don’t have to be changed, but they could be depending on your ambition. An attack doing 1d3 damage reduces to 2 points, not 1.
Thus: Arnold Littleworth, under this system, has a Bathrobe of AC 4, which is equal to Chain + Shield. His Deflection class is 11 (base) -1 (poor Dexterity) +1 (equivalent to shield) = 11.
If, solely for the sake of science, Martin le Black attacked Arnold with his +2 sword Bazilien, his attack roll would be executed normally, hoping for a roll equal or better than 11. Because Arnold’s Bathrobe is equivalent to Chain armor, the damage from Bazilien would be 1d4 (starting from 1d8 and reducing two steps) +1 (strength) +2 (magic).
Action |
Normal B/X D&D |
Experimental System |
Martin hits Arnold … |
60% of the time |
80% of the time |
On average Martin inflicts |
7.5 damage |
5.5 damage |
Expected damage per round |
4.5 damage |
4.4 damage |
Note a couple of effects from this experimental system:
- Armor reduces damage, it doesn’t keep you from getting hit in the first place.
- Magic-Users and Clerics can make “touch attacks” to overcome Deflection Class much easier than AC
- Characters are hit more often for less damage. Armor is approximately twice as useful as before, which helps Level 1 wimp-o’s.
- Damage reduction is neither fixed nor does it require an extra roll, i.e., it’s unpredictable without slowing play
- Against a guy with heavy armor, a dagger +1 does the same damage as a normal sword (more, on average, since it hits more often): magic is cool
- Heavily armored knights are slow and easy to hit, but very difficult to wound without magic.
- The special thing about Frodo’s undershirt is that it was extremely lightweight and easily concealed – like not wearing armor at all.
- Maybe someone other than me will enjoy the strategic effects of Encumbrance… oh who am I kidding
Just to see what it would look like, here is the comparison for a duel between Martin le Black and Hanna Darrowkin, using their stats as of 1/9/2011:
Action |
Normal B/X D&D |
Experimental System |
Martin hits Hanna … |
25% of the time |
55% of the time |
On average Martin inflicts |
7.5 damage |
5 damage |
Expected damage per round |
1.875 damage |
2.75 damage |
Action |
Normal B/X D&D |
Experimental System |
Hanna hits Martin … |
30% of the time |
60% of the time |
On average Hanna inflicts |
3.5 damage |
1 damage |
Expected damage per round |
1.05 damage |
0.6 damage |
What’s happening here is that Hanna, physically weaker, is using what amounts to an ordinary sword to attack a stronger foe armed with a larger, more heavily enchanted blade. Both duelists are very heavily armored, but over time, Martin’s superior strength and magic can punch through the Halfling Hero’s defenses.
I still need to figure out:
- What to do against touch-style attacks, like Wights and Vampires? They become a lot deadlier under this system.
- Do Hit Dice change? I’m thinking that combat between heavily armored dudes would take too long at standard Hit-Dice values.
- Maybe each type of armor stays vulnerable to a particular type of damage (Piercing, Slashing, Bludgeon), if people think armor otherwise is too good.
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