My (Better) Damage Mechanics

I'm alive.

I don't like hit points. They're fictionally confusing (meat points, etc.), and worse, they're boring. You always know how many HP you have, and that means you always know exactly how much damage you can survive. As you level up, combat becomes theoretically more survivable, but also consistently takes longer while you and your opponent remain equally matched. I don't like players being able to rely on that; a fair fight should never be that safe or predictable.

This is what I'm going to use instead from now on.

Damage

Hit points no longer exist. Damage still works the same way: attacks deal points of damage equal to the roll of a damage die (or dice) based on the attacker's weapon. A dagger deals 1d4 damage; an axe, spear, staff, or arrow deals 1d6; a sword deals 1d8 (because of its bigger cutting edge than an axe--the downside is that it's way more expensive, not useful as a tool, can't be thrown, etc.); a two-handed polearm, battleaxe, or longsword deals 1d10.

Wounds

Instead of taking away HP, damage causes wounds. A wound is always a physical injury in the fiction--if you're wounded, you've been cut, bruised, burnt, or whatever in a concretely established way.

Normal humans have 4 wound slots: 1 light, 1 moderate, 1 severe, 1 critical (named so as to correspond with the standard Cure spells). Light wounds are painful and hampering, but will get better on their own with time and rest. Moderate wounds are more painful and hampering and need treatment to heal, but aren't life-threatening. Serious wounds are "you're bleeding out": you're unconscious or otherwise incapacitated, and if you don't get help within the next few minutes, you'll die. Critical wounds are certain death--if not instant, then imminent enough to leave time for little more than dramatic last words, and beyond the help of any healer.

Each point of damage fills a wound slot. If you're unharmed and take 1 damage, you become lightly wounded; 2 damage, moderately wounded; 1 and then another 1, moderately wounded. When you're lightly wounded, you take -2 to all ability checks, attack rolls, and saves. When you're moderately wounded, you take -4. When you're seriously wounded, you go down and can't do anything more strenuous than crawl; if you aren't stabilized within 1+Con modifier minutes (minimum 1), you bleed out and die (you can also make one last dramatic attack or check, but then you die immediately). A PC with medical skills can stabilize a serious wound with medical supplies and a successful Int check; this takes a turn, during which the patient doesn't bleed out, but if the healer fails, the patient dies when the turn ends. A stabilized character is still seriously wounded; they can stand up and walk, but nothing more strenuous than that (which includes carrying a heavy load of gear).

Note that all this means being stabbed with a dagger has even odds to fatally wound you and a 1-in-4 chance to kill you outright (assuming the attack hits). A single spear thrust has a 2-in-3 chance to fatally wound and even odds to kill instantly.

Hit Dice

Everything that would normally have hit dice (so PCs, humans other than 0-level commoners, and monsters other than those with 0 HD) still does. Instead of rolling your HD to determine your HP, you keep them as a pool of dice.

When you get hit, before damage is rolled, you can spend any number of your HD to try and turn the blow. Roll those HD, add your Con modifier to each, and reduce the damage of the attack by the total. Any damage that gets through wounds you. All HD you roll are "exhausted." When you rest in a relatively safe, comfortable place for a night (so outside of the dungeon), you regain all exhausted HD.

Exhausting HD represents fatigue, minor scrapes and bruises, and diminishing luck, the way losing HP normally does when they're not used as meat points. The difference is that you can never know exactly how much luck you have left. If you're a 6th-level fighter up against a farmer with a spear, you can fight conservatively by only spending 1 HD each time the farmer hits you, but he might still get a lucky jab past your guard (you roll low on your HD, he rolls high for damage) and end you right there. The only way you can be completely sure of your safety (assuming you have a Con modifier of 0) is to blow all 6 of your HD the first time he lands a hit, leaving yourself exhausted and vulnerable if he manages to hit you again. If you're up against another 6th-level fighter, things become even less predictable--even if you both fight conservatively, the duel might drag on for many rounds or end in a single lucky strike.

This is a lot of text, so have some Berserk to break it up. Guts is probably fucked here
even with normal HP, but with these rules, he's fucked sooner.

Recovery and Healing

A light wound will heal in a week of normal (non-adventuring) activity, minus days equal to your Con modifier.

A moderate wound needs treatment to begin healing. A PC with medical skills can do this with medical supplies and an hour's work, or you can go to a doctor. Once treated, a moderate wound becomes a light wound after d6-Con modifier weeks (minimum 1) of non-adventuring activity, at which point it heals as a light wound. If you spend your recovery time on full bed rest under the care of a skilled healer, it's d4 weeks instead of d6.

A serious wound that's been stabilized can be treated like a moderate wound, and heals the same way (after which it becomes a moderate wound, which then has to heal up to a light wound). However, serious wounds leave lasting marks. Whenever you're treated for a serious wound, reduce a random ability score by 1d4 and gain a distinctive scar. (I'd ignore the ability score loss if your rules don't have PCs' ability scores increase as a standard thing; the new version of my hack I'm working on probably will, so this is meant as the main counterbalance to that.)

Instead of their normal effect, Cure spells heal wounds of their corresponding level immediately, skipping past the levels below to restore the subject to full health. Cure Serious Wounds doesn't prevent ability score loss (if you're using it) or scarring. A Cure spell won't do anything for a wound greater than its effect--Cure Light Wounds can't reduce a moderate wound to a light wound. Even magic has its limits. As a tradeoff, because wounds don't scale with level like HP, all Cure spells stay consistently useful at all levels, instead of Cure Light being obsoleted by Cure Moderate and Cure Serious.

Next Time

Like I mentioned, I'm working on a new build of my hack. I kind of want to put it in zine form this time; regardless, I'll probably post it here in full once I have it in something like a usable state. Meanwhile, I'd like to start putting some of my general rules ideas up here. Stay tuned if you like reading the words that come out of my head.