Just the right amount of damage

[Pussycat669]

I've been asking people at random about this for around two days now so putting the question here as well shouldn't hurt.

I guess most people here are familiar with Doom. Let's say you got the same Health system with a corresponding Portrait but instead of using one pool of hit points for the entire body, the health is spread over several partitions like in Deus Ex.

My Problem is that if I want to calculate the 'total damage' of the entire body, I can't simply use their percentage portion of the overall health since they aren’t equally important. Take the difference between Arms & Legs (which could only be broken at worst) and Torso (which destruction would mean death) for example. So if both arms and legs are at 0 HP that would mean a total damage of 50%. However, if the Torso would be 1 HP while Arms & Legs are at full health that would mean the total damage would rise above 90% regardless since the imminent death of the PC should be a concern to the player. Although I've found a couple of solutions they are rather coarse and inflexible (say if I want creatures with more limbs etc.). Maybe I'm just too daft but I simply can't think of any usable formula to calculate the importance of the different body parts dynamically.

 

[Zomg]

Multiply limb health by 1 - x^a, where x is how damaged the limb is (1 - current hp/max hp) and a is a constant you pick to taste (the higher a is, the more damaged the limb has to be before it counts), then put them in the (weighted) average with head and torso health. So, dynamically, every body part has two vital constants - a constant weighting of total importance (the constant of weighting in the average) and a constant of, uh, urgency?, which is that "a" constant.

Why do you want to bother having an "average health" when you can just track the limbs individually?

 

[Jormungandr]

Let's say you get your arm blown off. If you subsequently died, it wasn't from the lack of arm so much as the blood loss. If you get your torso blown open, you may die either from the damage to vital organs or, again, from blood loss. And massive blood loss usually acts out as loss of consciousness and then death.

So. What you could do is have a Stamina Meter in addition to (or in place of) Health. Damage to or loss of limbs results in that meter depleting at a rate proportional to the amount of damage suffered. So damage to a limb results in a gradual bleed, whereas a lost limb will leave you gushing quickly to your doom. Damage to the torso would do the same thing, but also have a greater chance of outright death due to organ damage.

So you could just leave the torso/head as the only "overall HP" to reflect organ damage and leave the limbs to contribute to bleeding.

 

[Lord Rocket]

I'm of the opinion that keeping track of each body part individually is stupid, basically because of the things Jormungandr said - you know, blood loss and that. You have arteries everywhere, after all, and people being unkillable if shot in the limbs is pretty much Hollywood anatomy.
I personally would recommend one big wound track, with additional effects if you're struck in the limbs or head or whatever for a certain amount of damage. So, X damage breaks bones, Y damage makes it fall off, or whatever you please. Consequences as per the area struck and the designer's whim.

 

[Pussycat669]

Why do you want to bother having an "average health" when you can just track the limbs individually?

Pracmatical reason of sorts. I wanted to use one of those old classy RPG user interfaces with portraits on one the side of the screen. Since I'm using Inform 7 however and creating a bunch of windows (which are also seperated into three different kinds of windows with different functionalities) is a rather awkward task, I needed something as minimal as possible. That's when the Doom nostalgia hit me. Instead wasting a week or two putting extra text windows (for HP) beneath the graphical windows (for the portraits), I would simply manipulate the portraits themselves to give a rough feedback to the player about the PC or NPC's whell-being. Hence I needed the average health to decide which current image for the character in question should be chosen.

Anyways, your formula seems to be just the thing that I needed. Thanks.

 

[J1M]

Figure out what the minimum damage required to kill the person is. That is your overall health total. As long as you can't be shot in the arm forever without some sort of consequence to the torso, this should work well.

 

[LastAngryBat]

Check out the Inquisitor pnp damage rules. It has location damage and an overall System Shock(he's dead Jim) value as well as consiousness