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Old 09-22-2021, 05:31 PM   #1
draxdeveloper
 
Join Date: Sep 2017
Default Damage to Force (in Newtons or any other unit)

For immersive reasons in my setting, I need to have a real world equivalent to damage values (or something that looks like it).
I am thinking taking the damage necessary to pierce thought something and take this value and compare to the value in N to do the pierce the same surface.
To blunt damage, maybe I could use bend instead of pierce thought?
To cutting damage... Have no Idea.

Other type of damages like poisoning I don't know if I can have something, but I can say that it would be as destructive than piercing thought a certain surface?

Any suggestions? Do you think this would work?
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Old 09-22-2021, 06:23 PM   #2
whswhs
 
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Default Re: Damage to Force (in Newtons or any other unit)

Newtons as such aren't a good measure. You can cut yourself fairly seriously on the edge of a newly sharpened knife, but the surface area of the edge is quite small, so the total force applied may be very small. If you applied that same force via a flat surface like the skin of a basketball, you might hardly feel it and you certainly wouldn't suffer any damage. Pressure (in newtons per square meter, or pascal) is a more relevant concern than force.

I think, though, that total energy transferred may be still more relevant.
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Old 09-22-2021, 06:34 PM   #3
Anthony
 
Join Date: Feb 2005
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Default Re: Damage to Force (in Newtons or any other unit)

In addition to force not being a terribly good measure for most types of damage (though it does have situations where it matters, mostly in a load-bearing context), it's actually quite hard to figure out what the amount of force in any impact actually is.
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Old 09-22-2021, 08:56 PM   #4
Anaraxes
 
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Default Re: Damage to Force (in Newtons or any other unit)

If the goal is to figure out whether or not you can move something by hitting it with an attack, then for muscle-powered attacks we've already got rules for shoving and throwing things (B353). Use the character's ST value. The damage multipliers on a weapon will either be irrelevant or actually disadvantageous. (If you're merely trying to move something, you don't want to poke into it; that's wasted energy for this purpose.) For non-muscle-powered attacks, you could try taking the damage dice and look it up on the ST-powered damage table in reverse to get an effective ST value. You probably want to limit the effect to explosions, impact damage, etc, since fire or laser beams aren't good at moving things they affect. (Still a pretty horrible oversimplification, but it's easy to do.) If the goal is to figure out whether or not you can damage an object, then there are rules for attacking objects.

What other uses do you foresee for applying a force in a game situation?

If you need Newtons as a unit, then you can use the lifting rules to get a force value for a given ST. (If you can just barely lift a given mass, then you're just capable of exerting the same force as does gravity.) One lbf (pound (force)) is 4.45 N, so just multiply by the lift values.
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Old 09-22-2021, 10:13 PM   #5
Fred Brackin
 
Join Date: Aug 2007
Default Re: Damage to Force (in Newtons or any other unit)

Quote:
Originally Posted by Anaraxes View Post
If You probably want to limit the effect to explosions, impact damage, etc, since fire or laser beams aren't good at moving things they affect.
Piercing damage is terrible at moving things too. Bullets do damage by with kinetic energy divided by units of surface area. Knocking things around means quantities of transferred momentum.

Momentum s a straight mas x velocity while kinetic energy is mass x velocity squared. Bullets have very, very little momentum.

It might be momentum that the OP wants but trying to handle these sorts of combat situations with simple math usually means too much simplification for real utility.
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Old 09-22-2021, 10:43 PM   #6
draxdeveloper
 
Join Date: Sep 2017
Default Re: Damage to Force (in Newtons or any other unit)

My main concept is to give a reason to damage.

In my setting, a group of people can access any group of information (with limitations) and compress it in a coherent data. This data is flagged with a name (like ST and HT, but I expanded the attributes using PW9).
Now they have a group of data called ST (Example) they can access the Source, that is something that have all information in the world, they can't exactly search anything there easily but they can know the average of all humans (or all living beings, depending what they want) of that data, thus they really know what would be the average ST of all humans and marked it as 10.
They did it with all stats, skills and so on that we have on a character sheet. That way the game info are also in game info and what you see in your sheet makes sense in the game world.

That said, the only thing I could give a at least minimal explanation is damage. I could not think what exactly the damage data would be measuring. Maybe there are a way that is more simple to justify that?
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Old 09-22-2021, 11:05 PM   #7
Fred Brackin
 
Join Date: Aug 2007
Default Re: Damage to Force (in Newtons or any other unit)

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Originally Posted by draxdeveloper View Post
That said, the only thing I could give a at least minimal explanation is damage. I could not think what exactly the damage data would be measuring. Maybe there are a way that is more simple to justify that?
Damage is that which detroys Hit Pts. Any given numerical amount of damage is a similar result of many possible different forces.

Amounts of Crushing damage can end up similar to an amount of Burning damage but that's all different inputs ending up at an equivalent place in output.
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Old 09-23-2021, 04:55 AM   #8
malloyd
 
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Default Re: Damage to Force (in Newtons or any other unit)

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Originally Posted by Fred Brackin View Post
Damage is that which detroys Hit Pts. Any given numerical amount of damage is a similar result of many possible different forces.

Amounts of Crushing damage can end up similar to an amount of Burning damage but that's all different inputs ending up at an equivalent place in output.
Yes. Hit Points, and thus damage, is an unrealistic abstraction for playability. There simply is no linear scale of how much something is hurt between perfectly fine and "dead" (itself quite hard to define), which is what hit points fundamentally are. You can't compare a broken leg to third degree burns over 10% of your body, to exposed to 20% of the LD-50 of a poison and decide which of those brings you closer to death, and you certainly can't add up all 3 of them and be sure that does (or does not) kill you. You can't find a realistic equivalent because there isn't one.

A more realistic rule would give you some chance of death from any particular source that was more or less independent of any other, you couldn't add damage together. But you need the additive linear scale to do attritional combat, which is essential to most games combat mechanics. That's something that entered RPGs from their wargaming past (fraction of people in a unit who are dead is realistically a much more linearly attritional sort of thing that individual wounds after all) and become standard. Some games try something else (Ars Magica's Soak roll has some of that independent risk character for example) but it is always hard to write rules for things that are hard to assign numbers to.

Which is of course why games even *have* stats. You need a relatively small set of numbers for the game engine, even if the stuff doesn't perfectly correlate in reality. That holds for everything really if you start to look at it closely enough - you have a Strength stat, not a force curve for each muscle in each of several different directions.
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Old 09-24-2021, 07:11 AM   #9
Varyon
 
Join Date: Jun 2013
Default Re: Damage to Force (in Newtons or any other unit)

Quote:
Originally Posted by draxdeveloper View Post
My main concept is to give a reason to damage.
Damage is a bit... abstract. Consider a 9mm pistol, which does (IIRC) 2d+2 pi. That's anywhere between 4 and 14 damage, when in reality the penetrating power of one 9mm cartridge and another of the same make, being shot from the same weapon, are very similar. Against an unarmored target, a low damage roll may represent hitting somewhere relatively non-vital (an example is hitting the "love handles" on the side of the waist) while a high damage roll represents a more serious hit, probably closer to the core (but not quite the Vitals) of the Torso, or a bone hit on a limb (crippling it). Against a target with armor roughly on the same scale as the weapon (~DR 8 or 9 here), these may well be reversed - a low damage roll means hitting somewhere well-armored, which may well be somewhere that would be a serious hit on an unarmored target, while a high damage roll could represent hitting somewhere that's lightly or even unarmored, which is probably a relatively non-vital area.

Then, there's what "penetrating" armor means for a crushing attack. Particularly against rigid DR (where Blunt Trauma rules don't come into play), this may well represent some degree of the damage to the armor, but you're unlikely to be literally breaking through it - rather, what you're doing is overwhelming the armor's ability to absorb and spread out (over area and time) the impact to avoid wounding, such that enough force gets through quickly enough to still injure the target. In other words, you're hitting hard enough that the armor is bludgeoning the target.

For a cutting attack, realistically a "penetrating hit" is one that works like above, with the impact force being enough to make the armor bludgeon the target. This would actually convert damage from cutting to crushing - note GURPS Low Tech has some optional rules for this. Part of those rules is that if you manage to deal more than twice the DR in damage (so more than 8 cut against DR 4), you've cut through and your damage is considered cutting again. This isn't all that realistic, but realistically modeling a cutting weapon going through armor would be a nightmare, particularly if you're dealing with a large cutting surface (like a sword) - you start with a relatively small part of the cutting surface impacting the armor, then if there's sufficient pressure to make it through it starts a tear/break, and then as more of the blade comes into contact with more of the armor, the remaining pressure gets spread out, but now (IIRC, it's been a while since I tried to make my abandoned Armor and Wounding Overhaul) instead of dealing with the armor material's yield strength you're dealing with the (lower) shear strength.

Trust me, trying to equate pressure with armor penetration is a rabbit hole you don't want to fall down. It's probably OK for piercing attacks (for determining the penetration of firearms), but rapidly becomes a nightmare for other attack types.
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Last edited by Varyon; 09-24-2021 at 08:45 AM. Reason: Actually, I may have overused actually, so I actually removed a lot of instances of "actually."
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Old 09-24-2021, 11:23 AM   #10
Polydamas
 
Join Date: Jan 2006
Location: Central Europe
Default Re: Damage to Force (in Newtons or any other unit)

Quote:
Originally Posted by draxdeveloper View Post
For immersive reasons in my setting, I need to have a real world equivalent to damage values (or something that looks like it).
I am thinking taking the damage necessary to pierce thought something and take this value and compare to the value in N to do the pierce the same surface.
To blunt damage, maybe I could use bend instead of pierce thought?
To cutting damage... Have no Idea.

Other type of damages like poisoning I don't know if I can have something, but I can say that it would be as destructive than piercing thought a certain surface?

Any suggestions? Do you think this would work?
What you want can't be done. Bullet penetration is based on a simple physics model by Douglas Cole of Gaming Ballistic. It still needs to take three variables as input and there is a physics professor in the United States who does not like his model. (But Cole is an engineer with postgraduate degrees too, and I can't track down the works the physicist cites or judge what is a reasonable simplifying assumption).

Trying to model bullet damage is something which gets hunters and ballisticians and engineers and pathologists screaming at each other. And as for hand-held weapons ... those are even harder to model! If teams of PhDs throw up their hands, gamers are not going to come up with a good-enough solution.
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