Presented in order of confidence, most to least.
Here's a system for HP I've been screwing around with for a little while. (As usual, dS is "dice size," so +1 dS changes a d4 to a d6, and -2 dS changes a d12 to a d8.) This is mostly stolen from Jared Sinclair's 6e.
When you sleep, roll [level]dX. If the new total is higher than your previous HP, that's now your current HP. Resting will never lower your HP.
By default, dX is a d8. Here's what can change that:
- -1 dS for each of the following: you go to sleep while...
- in your armor
- without a bedroll
- seriously wounded (like, from a death & dismemberment table, not just regular combat damage)
- +1 dS for each of the following: you go to sleep while...
- having just finished a hot meal
- in a real, actual bed
- freshly cleaned and groomed
Max dX is a d20; min dX is a d1.
WHY THIS IS COOL
All that camping shit players love to ignore really matters. You need a bedroll, and a tent, and a mess kit, and a fire, and clean water, and a place to actually fucking sleep. On the flipside, buying a room and meal and bath is suddenly extremely worth it, because it's the quickest way to get back all your HP.
Imagine, for a second, the level 3 adventurer that just crawled out of the sewer-dungeon after having their gear stolen by frogpeople: they're wet, cold, and hungry. That's a d2, meaning until they can find a good place to sleep, their new maximum HP is a big ol' 6.
By contrast, imagine that same adventurer spending a night at the inn in town: they're warm, they're fed, and they took a bath with real soap. Their die is a d20, meaning their max is 60 HP. Which, you know, is ludicrous, but that'll take months or years of resting to reach (because, remember, it's not additive—new HP only increases if it's higher than the old).
I also like this because it captures the "resting for longer is good and necessary sometimes" thing that Grit & Flesh does without needing to mess around with secondary HP tracks.
Here's an inventory-exhaustion system I've been screwing around with for a while. This is mostly stolen from Grave and Boots Full of Mud.
You've got your inventory slots, yeah? Use those. (You might want to give players a few more than normal—I usually do CON + STR these days.)
Whenever you take a point of exhaustion, fill one inventory slot. If you end up with more filled slots than you have inventory space, you start slowing down and eventually can't move anymore.
Here are some things that mean you take a point of exhaustion:
- Crossing a gradient line of elevation (cf. Boots)
- Crossing a river
- Traveling every hour past the normal daily amount (usually 8 hours)
- Traveling a watch (4 hours) at a faster pace than normal (usually +1 mph)
- Staying up for a watch (4 hours) when you should be sleeping.
- Exhaustion-attacks and certain illnesses, like plague bugs or whatever
- Pulling a stunt and an attack on the same turn in combat (cf. Grave, basically imagine baby's first Action Surge)
- If you're playing 5e, have things that normally deal 1 Exhaustion (zerker's frenzy, for example) deal 1d4 slots or 1d6 slots or something
If you're using my resty HP, clear exhaustion every night equal to highest single die rolled.
WHY THIS IS COOL
It makes exhaustion this extremely palpable thing that suddenly really matters, but also doesn't involve fucking around with either your HP or some additional track. It bites you where it hurts, but it's easy to predict. If your players are paying attention and managing their travels well, they'll be fine; if they get lost or lose their focus, they'll suddenly have no inventory to work with and that sucks big time.
If you use the stunt-exhaustion thing from Grave, which I like, it also means you get a cool Thief / Fighter distinction solely based on inventory: thieves wear light armor and carry light weapons so they can do lots of cool stunts in combat; fighters wear heavy armor and carry heavy weapons so they're more reliable, but every stunt they pull matters a lot more.
It's also just very... hackable. Modular. It's dead simple to add in more effects that inflict exhaustion, or have magical healing clear exhaustion, or whatver else.
CALLED SHOTS ONLY
This is a weird one. It doesn't play nice with resty HP, since it doesn't actually use HP (lol). Entirely untested.
Use your sandwich AC for attacks, where you've got to roll equal-to-or-under your attack stat but over your opponent's AC to hit.
Every time you attack your opponent, say where you try hit them: torso, a limb, their head, or whatever.
Their AC changes based on where you hit them:
- Torso: +0
- Limbs: +3
- Head or neck: +5
- Smaller specific part, like eyes or hands: +10
Here's what armor adds:
- Leather, +2 AC
- Chain, +4 AC
- Plate, +6 AC
- Dragonscale, +12 AC
The armor your opponent wears only covers so much. A breastplate protects only the torso. A helmet protects the head, but almost never the eyes. There's a constant dance of figuring out where the best place to hit them is.
If your attack is equal to or 1 more than their AC, it's a graze. A glancing blow. Cuts, scrapes, bruises.
If your attack is 2 or more than their AC, it's a hit. A solid strike, it'll do damage. Broken bones, flesh wounds, serious injuries.
If your attack is 5 or more than their AC, it's a critical hit. Severed limbs, crushed rib cages, heads rent in twain.
There's no HP here, just diegetic damage. If something would kill someone, it kills them. Bear in mind that a graze to, say, the eyeballs is going to do a hell of a lot more than a graze to the ribs.
WHY THIS IS COOL
There's a dance to every fight. Imagine my opponent: they've got a breastplate, leather gauntlets and greaves, and a chainmail coif. If I attack their torso, their AC's about 4. Decent odds for me, but even a solid hit is not guaranteed to knock them out of the fight. If I attack their head, their AC's about 9, but even a graze will do serious damage. If I attack their sword-arm, their AC's about 5, and a solid hit will seriously dampen their ability to hit me.
It means that every swing in combat is a gamble, a decision. It probably does slow each turn of combat down, but it means each turn can potentially end the fight. There's no whittling-down of HP real slowly until the monster drops dead—you either kill them, or you don't.
It also means you can make combat into more of a puzzle. Take a dragon: its weak spots are its eyes, its mouth, and whatever hole it has in its diamond belly-armor. Those are hard to hit, but are always going to be easier—and deadlier, probably—than trying to punch through dragonscale.
Again, this is completely untested, but it's my hope, my suspicion, that this kind of system enables combat to be less about cronching numbers against each other and more about figuring out ways to exploit your opponents' weaknesses. Hopefully.
Let me know what you think.