I liked that rule in DW because having different damage die per weapon has niggled me for a while. It requires a double-think on the part of the verisimilitude of what damage and HP mean. Consider:
- Hit Points are abstract. They represent how much moxie and luck and chutzpah a character has to absorb near misses and glancing blows. They're not really you getting hit--at least not in a meaningful way.
- Different types of weapons will cause varying degrees of tissue damage. A handgun is going to cause a different wound than a chainsaw. A big ass claymore is going to cause a different wound than a nunchaku blow.
These two ideas aren't entirely congruous.
Moreover, despite having a fairly abstract combat system, D&D's weapon choices were often rather bland. Sure the quarterstaff has the two-handed and versatile weapon properties, but...so what? In several editions, I found that the group was usually choosing the same weapons because "they were the best" mechanically. That kind of sucks, doesn't it? Shouldn't your weapon choice be thematically appropriate and representative of your character's fighting style?
Anyway, this here isn't anything groundbreaking, but it was an idea that I had on a walk this morning. If I was ever going to run a Oriental Adventures-esque game, I'd probably shop these as house rules.
Each player character chooses a signature weapon. The barbarian might choose the double-handed axe or the claymore, while the thief chooses the dagger--or visa versa.
When wielding your signature weapon, you deal d8 damage. If it's a two-handed weapon, you deal d10 damage instead.
If you're wielding a weapon that you're proficient in (but isn't your signature weapon), you deal d6 damage.
If you're wielding a weapon that you're not proficient in, you deal d4 damage.
Shuriken means "hidden sword." Throwing stars or daggers weren't really designed to do massive amounts of damage, but throwing a small blade into your opponent's face when they're not expecting it can be pretty effective. Therefore:
If you use a new improvised weapon for the first time during a campaign, you deal d12 damage.
If you use an improvised weapon for the second time, it's treated as a trained weapon (d6).
Each subsequent use of that improvised weapon deals d4 damage.
So, the first time you're in a bar and decide to pick up a bar stool and smash it over your opponent's head, you deal d12. But barstools aren't really made for weaponry, so the gimmick gets old quick and each barstool attack will yield diminishing returns. However, if you'd like to throw the boar's head mantelpiece or a fisherman's net or a roof tile or a dead goblin, the first time you use those you also get to roll a d12. Players should utilize the environment in interesting ways.
In this system, the damage dice represent "threat" and "skill" more than their wrecking power.
If you want to see two house rule systems for LotFP that treat weapons differently/interestingly in ways beyond varying damage dice, check out Last Gasp Grimoire and Ten-Foot Polemic.