Alright, so I have a slight issue. I can't seem to find a way to make a particular thing in a game realistically more difficult to pull off and I need to. Now, the game isn't made yet, but I just realised how little it's going to take to do something and how absurdly effective it is. Basically, in this game there's ten areas on the opponent that can be damaged by your attacks. The right and left legs, the right and left arms, the abdomen, the chest, the neck, the head, the heart and the brain. There's sections mapped onto each for other effects, but that's the gist of it.

The problem I am having is that a shot through the heart, note that the game only counts the ventricles as heart shots and doesn't count shots to the atrium because they're totally different, while not an instant kill most of the time, is unsurvivable even with medical attention due to extremely heavy DOT that lasts an impossibly long time and a special constant damage effect (if large enough) that never goes away. This is realistic, being shot through the heart in any situation you'd find in game would be an absolute death sentence. (The circumstances in which you could actually survive such a wound are squarely in the "not goanna happen" category anyway, and they're impossible to replicate in-game.) The problem is, the heart is not an especially hard target to hit and such a rapid death is a big deal in a game where it's normally rare for a single gunshot wound to kill you and dying from anything tends to take rather a long time.

Now, it's a cooperative game and not a competitive one on the rare instance it's multiplayer at all, but it's a serious issue. If the player can just shoot every enemy through the heart, they're going to do it and never do anything else. And worse, many enemies in the game also use guns, and if one of them manages to shoot the player character through the heart they're done for in VERY short order. But here's the thing: I don't want to make doing this weaker, because honestly that's about what a heart shot is like anyway, I just want to make it harder to do in actual combat. That way, a sneaky player who manages to get the drop on their enemy can pull off a heart shot for full effect, but the player won't get shot in the heart by the first thing they fight smart enough to use a gun and have to start a new game.

How does shooting work in your game? (controls etc.)
Is therr room for body armor deflection?

Do something funny like making the players weapon jam every time he is about to get a heartshot in a situation where you dont deem it acceptable.

Or change the game design on a larger scale to not make it such a problem.

Or add some random element to make it not successful most of the time (your arm is shaking and the gun is shaking all by itself and the bullet is shaking while flying because turbulence and the enemy is shaking while trying to avoid being hit and the heart is rapidly shifting position because adrenaline).

How does shooting work in your game? (controls etc.)

It controls like an FPS, for the most part. There's more key combos and such, like the ability to switch from one-hand to two-hand wielding and back, and more attack options, but that's the only real difference. Here, take a gander at the (default) control scheme. It's listed mouse/keyboard, gamepad. (The button names for the gamepad are those of a Microsoft Xbox 360 controller.)

[spoiler]Fast walk: WASD, left stick
Slow walk: Alt+WASD, left stick+click left stick
Jog: Shift+WASD, left stick
Sprint: Shift+Alt+W, left stick+click left stick
Stance: Ctrl, click right stick
Jump: Spacebar, A
Left primary attack: Left mouse button, left trigger
Right primary attack: Right mouse button, right trigger
Left secondary attack: Back mouse side button, left bumper
Right secondary attack: Forward mouse side button, right bumper
Left tertiary attack: Left action+primary
Right tertiary attack: Right action+primary
Left guard: Left action+secondary
Right guard: Right action+secondary
Left action/contextual attack: Z, X
Right action/contextual attack: C, B
Switch one-hand/two-hand: left action+right
Command: Q+Number bar 1-8, Y (hold)+D-pad
Target lock: E, Y (tap)
View/Mode: F, Back
Adjust zoom: Scroll, D-pad (when aiming)
Item select: Number bar 1-8, D-pad
Menu: Esc, Start
[/spoiler]

Some of these change the way the game controls, or are heavily contextual. Target lock is both, basically being an on/off button for the autoaim in first person (the autoaim is strongly limited, stat-based and frequently inferior to manual aiming for a skilled player even when you're in range) and a true target lock in third person. (In third person, locking onto a target makes all action relative to the target, the game aims for you, and this basically gives you action game controls like Dark Souls or Fable.)

Is therr room for body armor deflection?

Armour provides several kinds of protection in this game. The first is damage reduction, simple but modified divisively by penetration and thus less simple than normal, the second is damage division, which goes into the penetration system. Basically, if the attack has more penetration than the DD of a target, it does full damage and punches through to hit what's behind it (say, the person wearing a suit of armour, or maybe the guy hiding behind a wall, or the guy behind the guy you're shooting, or with a rifle the guy wearing a suit of armour hiding behind the wall behind the guy you're shooting) but if it has less penetration than the DD of the target the penetration is divided by the DD and the damage is multiplied by the result. Both are type specific. There's also immunity, but even if armour has immunity that doesn't help the wearer at all because it only applies to the damage the armour takes. (It's just a percentage anyway.) Deflection isn't a thing, but angle impacts DD. Straight-on, DD is at the base value, at a 60 degree angle it's twice as high, at 90 it's infinite. I'm sure you're familiar with the math involved.

Do something funny like making the players weapon jam every time he is about to get a heartshot in a situation where you dont deem it acceptable.

That would be cheating.

Or change the game design on a larger scale to not make it such a problem.

I'm not changing everything about the game over one balance issue.

Or add some random element to make it not successful most of the time (your arm is shaking and the gun is shaking all by itself and the bullet is shaking while flying because turbulence and the enemy is shaking while trying to avoid being hit and the heart is rapidly shifting position because adrenaline).

The heart doesn't change position, but most of the rest is already true. Your gun wobbles, although you can steady it somewhat, the bullet takes time to travel (it's realistically fast, though), slows down and drops, and almost none of the animations you'd see in combat have the character's torso at all stationary. Hitting the heart is already hard compared to other areas of the body, but it's not hard enough for such a massive result. I mean, normally with a single gunshot wound to the chest you wouldn't bleed to death at all, much less do it quickly, and a 9mm going from taking off just short of half their health (no laughing matter, by the way, you get weaker as you lose health and by half might be having issues staying conscious) by the time the bleeding stops ten minutes later to killing them dead with no chance of survival in less than a minute is rather enormous for a ten centimetre difference in shot placement. Most players are smart enough to understand this, and rapidly spam shots at centre mass knowing at least one will probably hit the heart.

If it controls like an FPS, then would it really be that easy to hit so small (and hidden) a target as a human heart? Even head-shots take some skill in first-person shooters, I believe. (Conversely, if the enemies are huge then they might take some time to fall even after a shot to the heart, or may simply have enough flesh and bone between skin and heart that a single shot may not penetrate far enough.)

However, your control list mentions a "target lock" ability--does that allow the player to "lock" to a specific part, such as the heart?

If it controls like an FPS, then would it really be that easy to hit so small (and hidden) a target as a human heart? Even head-shots take some skill in first-person shooters, I believe. (Conversely, if the enemies are huge then they might take some time to fall even after a shot to the heart, or may simply have enough flesh and bone between skin and heart that a single shot may not penetrate far enough.)

It's actually easier, I believe, to hit the heart than it is to hit the brain if, unlike most people, you know where the heart actually is. (Unlike in most video games, shooting somebody in the cheek or jaw isn't the same as shooting them in the forehead or anything even remotely close to it.) The heart may be smaller, but it moves around less and that's a big deal, especially since the bullets aren't hitscan.

But, keep in mind, not all or even most enemies are humanoid. If you're shooting a wild dog, for instance, it's not as hard to hit a specific body part because their body moves around less and moves more predictably. (And they don't move laterally, and can't dodge without rolling.) And a dog will die even faster from a heart wound that a human would. A lot faster, actually.

As for a huge enemy, it actually takes a pretty silly amount of meat to stop a bullet. Especially if you have a rifle. The sternum of a really large target might stop a pistol from reaching the heart, but there are few creatures large enough a rifle wouldn't do the trick. Although it is true that they would take a lot longer to die, but they'd take longer to die from any wound.

However, your control list mentions a "target lock" ability--does that allow the player to "lock" to a specific part, such as the heart?

It doesn't lock into specific body-parts as you please, in fact it actually aims for the stomach. (As in, the actual organ in the upper abdomen, not the area way below that usually thought of when the stomach is mentioned.) You can't even tweak the aim, the mouse (or right thumbstick) is instead used to switch targets. The issue is when manual aiming, going for the heart isn't hard enough for the player to ever do anything else.

Make the heart a smaller target internally? Have you acfually playtested that this would be the case to get heart kills?

Make the heart a smaller target internally? Have you acfually playtested that this would be the case to get heart kills?

No, I just know how hard it is to hit a target that size in a video game and have a pretty good idea about how much the rest complicates it and I strongly suspect it's not enough.

You can't make your weapons that realistically damaging and expect to have the same exciting, run-and-gun fights you see in a lot of FPS games.

Most gun fights are either extremely one sided (and over in a matter of seconds), or extremely long and drawn out, with both sides behind cover waiting for the other guys to run out of ammo, or for the artillery to come down, or for reinforcements to flank them... etc.

I'd say that if you want to keep that level of detail in how weapons work, you need to re-evalutate the pace of the game and the quantity of the enemies to a point where getting shot (pretty much at all) is expected to end the game.

If you are keeping the DOT that makes you bleed out from getting shot in the heart, are you also making it so that getting shot in the leg makes it so hard to concentrate that you pretty much entirely lose all your accuracy? Getting hit in the body armor your wearing stuns you b/c you've had the wind knocked out of you and without someone to drag you off behind cover makes you easy pickings?

Also, it seems that accuracy in your game is not realistic enough if it is that easy to hit the heart every time. A good marksmen might be able to reliably hit a target the size of the heart at a reasonable distance (changes depending on type of gun) from a stable position on a stationary target, but that will only be true for say... the first shot against a sleeping target or something.

So, to it seems to me that this is an issue where one mechanic has a level or realism that is out of place with the rest of the mechanics.

Also, it seems that accuracy in your game is not realistic enough if it is that easy to hit the heart every time. A good marksmen might be able to reliably hit a target the size of the heart at a reasonable distance (changes depending on type of gun) from a stable position on a stationary target, but that will only be true for say... the first shot against a sleeping target or something.

This pretty much echos my opinion. If you're making heart shots death shots, and if they are easy to hit, then you probably have an accuracy issue. FPS can get away with simplified hitscan weapons that are crazy accurate, I suspect your game would not. But then again, this could be all worrying over nothing, I think this may be a case of premature optimization, at least for enemies being hit by heart shots. For the player, you may end up wanting a completely different damage model, as it's hard to say without knowing your game, but I suspect that being sometimes instantly killed by enemies and sometimes not will probably not end up being very much fun.