Not organic, but in the classic trajectory game Scorched Earth, if your tank got damaged, then your maximum shot power was reduced proportionately.
It wasn’t usually a big deal, though, since (in most cases) your tank itself wouldn’t start taking damage until your shields were completely down, and most hits that took down your shields would probably be enough to kill you outright.
Well, maybe just too real to be fun. If, IRL, you had a guy carrying such a spell (like maybe a grenade) and he managed to throw it into the middle of the opposition, harming them all and none of yours, a hand-to-hand fight between groups would in fact be very lopsided.
Yes, pretty much. It certainly was a realistic game, in that if your party of X armed-to-the-nines samurai met a party of X+1 peasants with pitchforks, you really didn’t want to take your chances :). But it kinda killed any hopes of prolonged high adventure…
And annoying migraine headaches with head damage.
Call of Cthulhu: Dark Corners of the Earth had no life bars or other HUD indicators. Damage is shown by an “aura” or your breathing rate. If you took fall damage, you’d shatter your leg and need to splint it. Wounds caused bleeding etc. Not realistic in how fast they get fixed, but otherwise IIRC there was no “heal X hp” items, just heal over time so you couldn’t pop 10 aspirins and be fine. Also the only game I know of that simulates negligent discharges if you accidentally clicked while switching weapons. Also had a (hidden) sanity meter.
In Dark Souls, this applied uniquely to a specific boss. In video games (including Souls games), the opposite is often true for bosses, they get harder or have some sort of “rage” mechanic when they get to lower health.
Not for Great Grey Wolf Sif. At very low health he starts to limp and can’t properly swing his sword anymore. It’s kind of heartbreaking
I think a couple of the colossi in Shadow of the Colossus also do this.
There’s are also some scripted sequences of games that simulate this, but they’re generally not tied to your HP (for instance, the penultimate level of Journey simulates dying from exposure to cold)
In Dragon Age: Origins, your party members can’t be permanently killed, but every time they get knocked out they get a random injury which sticks with them until they get more substantial healing.
The recently released Pillars of Eternity has a system that’s like regular HP, except that you also have a much larger pool of health that takes damage at the same time. A character doesn’t suffer any penalties until their health gets low, at which point they stop being able to recover and risk actually getting killed.
Deus Ex had health for individual limbs. When you lost your legs you couldn’t stand up anymore and had to crawl around until you healed.
Cave Story has an unusual system in which killing enemies gets you little XP baubles that upgrade your currently equipped gun. When you get hit, though, you lose that XP and your gun becomes weaker.
In FTL, your ship has a hull strength which is pretty much just HP, but your systems can get hit individually, all of which have unique functions. Get hit in the weapons room, and some of your weapons go offline. Get hit in life support, and you run the risk of your crew suffocating. If your teleporter gets hit, you’d better hope you don’t have an away team that needs to be recalled. It can get really tense prioritizing which systems to repair first. Your crew functions at full strength until they die, though.
In the King’s Bounty games, your units represent a whole bunch of guys. As they take damage, some of them die and the unit’s strength falls proportionally. You have to recruit more minions to bring them back to full strength.
Way back in the Legend of Zelda, you had a special ranged attack that was only available when you were at full health. You lost it when you took any damage. It was never clear to young me whether Link was throwing his sword or it was some kind of magic blast that just looked like the sword. Throughout most of the series the games beeps at you when you’re low on health, which I think most will agree is debilitating in its annoyingness.
The Smash Brothers games work on the principle that you never get knocked out just for taking damage, but for going off the stage. The more damage you take, the further you get knocked back when you get hit. You never actually get KO’d from damage, just more likely to get taken out by a hit.
In general, I think most designers avoid punishing players too much for taking damage with good reason. Everyone loves a good comeback story, about how at your darkest moment, just on the edge of defeat you managed to pull through and snatch victory from the jaws of defeat. The more you hobble a player for taking damage, the more unlikely you make that comeback. Hobbling the player usually works alright in games with a high degree of resource management, Deus Ex or FTL, but in action oriented competitive games, most fighting games, it tends to just make defeat feel more inevitable and victory less satisfying. Maybe it’s not realistic that your fighter on the verge of defeat can swing as hard as at the beginning of the fight, but realism be damned it’s just more fun that way. The best compromise, I think, is to give a lot of visual and audio clues, things like panting or sagging shoulders, to indicate exhaustion without actually making the character weaker.
These are great responses, guys! Thanks.
Here’s another I just thought of: that great game Eternal Darkness, Sanity’s Requiem. I think you noticeably move slower upon being damaged. When your sanity is affected, you also can experience effects that may be distracting, or temporarily reduce your fighting capability.
Just remembered another one: In Blaster Master, in the EVA areas. You have a fairly standard health bar, you don’t take any penalties for being at low health, and health replenishment power-ups are plentiful… but you also have a separate bar for your gun power, every hit also decreases that, and gun power-ups are far less common than health. Given how much more powerful a max-level gun is than a min-level gun, or even than a penultimate gun, you really, really want to avoid taking even one point of damage.
There was something like that in the Way of the Samurai games : you had regular health that did nothing (or you died, that is) but you also had a sword-life meter that filled up whenever you either blocked or attacked into a blocking opponent (and would slowly empty otherwise). Once the meter was full, you lost one whole chunk of it. When the last chunk was out your sword broke, forever. Which was a bad thing because your combat moves were determined by your sword, and so were the unlockable moves. You could have two of the exact same sword but only one with the moves unlocked for example.
And naturally legendary swords started out with a longer meter to begin with so you had a neat dynamic where at the beginning you kind of went through crap swords all the time and a fight could suddenly go from “hah ! only two dudes, easy peasy” to “clink woops, run away run away run awayyyy” ; and later on while you were a lot more badass you didn’t want to run headlong into too many fights because you didn’t want to risk crapping up your megasword.
This is an interesting question, and it’s one that often comes up in discussions of pen-and-paper RPGs (like Dungeons & Dragons) as well.
There are two big reasons why representing injuries isn’t the norm.
The first is that it has a snowballing effect. If you make an injured character less effective, they are more prone to further injury and this will often lead pretty directly to death. Ultimately, it becomes a system that just funnels players into dying quicker (and, in PvP games, leads to matches becoming one-sided quicker). Games that handle this well can make it work, but it’s not always an appropriate solution.
The second, though, is a little trickier – in longer games, these kinds of mechanics can ultimately seem less realistic because your character will be recovering from serious injuries quickly. One recent example is in Far Cry 4 – your character is frequently digging out bullets, resetting dislocated digits, and bandaging major bleeding wounds. It’s fun window-dressing in a game that doesn’t take itself too seriously, but it does serve to draw attention to just how impossible your character’s ability to recover is.
Games are made of conceits and abstractions, and “health meters” have always been one of the trickier ones, because obviously real bodies don’t work that way.
I do realize its not the “official” explanation for it in most games but I’ve always treated hit points as a sort of how many attacks you can take before your luck runs out. So that you don’t actually get hit by every attack that reduces your health bar, they are all dodges/grazes/narrow misses and so on. Until your luck runs out and the next bullet/fireball/sword swing has your name written on it, and then you go down.
That explanation goes rather well with most cinematic battles in other medias too. Any big battle between the hero and the bad guy(s) usually has a lot of sound and fury and little actual damage until the very end.
The old MUD Gemstone had hit points, but also had debilitating effects based on injuries to areas (head, arms, legs, etc._ based on crits. I can’t remember the details, but it was pretty cool, especially if you were a stealth / ambush based character and wanted to target loacations with sneak attacks as a crit-stacker.
Or the game can go the whole nine yards in terms of realism, like *Pendragon *: if you get wounded or have bones broken, be prepared to spend entire months healing back up.
That was the presentation given in the original AD&D DM’s Guide. You (in theory) had the same 1d4 physical hit points as any other jamoke but your skill at dodging, parrying and otherwise avoiding damage stretched those points out far further than an untrained person. Having 80 hit points was the representation of your advanced skill.
But there was also the admission that it’s a game of fantasy heroics and it’s just less fun have your knight limping around on a bad knee and nursing a bruised shoulder that won’t let him hold a shield up for the entire dungeon.
Sure, but we’ve rarely had so much fun than when playing Warhammer 3rd Ed our knight took a Flesh Wound crit, then another Flesh Wound crit and then a Crippled Leg crit that the previous crits turned into an outright limb loss in a battle. The amount of Monthy Python jokes that triggered was epic.
Of course, Warhammer has a slightly different tone to it than D&D. 
…good gosh that was an awesome game. I remember one game that seemed to go on for ages, we had both injured our legs and were flapping about on the ground, and somehow one of us managed to kill the other. Then the next game :: thrust, parry, kill :: victory in seconds. I can’t think of another game experience like it.
The health+luck+skill thing is a good conceit, but then healing potions (or medkits) start getting weird. And, in the realm of videogames, there’s generally visual indicators that you’re actually being hit – clear animations, blood spatters, etc.
It’s messy!
This is actually a topic I’ve thought a lot about, because I used to dabble in RPG writing (and would love to get back to it, someday). The best version I’ve ever come up with is a combination Stamina + Health system, where you burn easily-replenished Stamina points first, representing last-second dodges, the fatigue of parrying or shielding strong attacks, etc, and start taking more-serious, slow-to-recover Health damage only after your Stamina buffer is gone. It’s not perfect, but I think it works well narratively for many cases.
Gunfire is the toughest case – gunshots hurt and the idea of surviving a series of hits is pretty implausible. It’s tough to make a realistic game out of that that’s actually fun.
The business of “only 1d4 actual hit points” is actually even more unrealistic: Real-life badasses really do take grievous wounds (or at least, what would be grievous wounds for normal folks) and keep on going.
Constitution bonus 
DragonQuest did this. I thought it looked like a very nice system. TSR musta thought so, too. They bought’em out and retired the game.