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Old 01-21-2012, 11:22 PM   #11
starslayer
 
Join Date: Dec 2006
Default Re: Cover DR and armour penetration

Quote:
Originally Posted by Ulzgoroth View Post
(200) resembles nothing real that I can think of, but it is very clearly defined. Throwing out that definition on intuition is not a good idea.

Though you may want to consider whether or not you actually think a 2d (200) attack is a good model for whatever it is that you're using that to represent, since you seem to think that it isn't behaving as expected.

I think you're underestimating the thickness of the planet. (200) is a lot, but not that much. However, yes, it will penetrate any normal human pretty much as if they weren't there. Or any normal automobile, or many buildings.

More to the point, though, the attack's effect on the target is governed by it's wounding type, not its armor divisor. As is always the case.
Well unfortunately 2d(200) was what I was dealing with because the PC had penetrating strike and was using a pistol and decided to shoot through the wall the enemies were hiding behind. So I'm not using 2d(200) to represent anything, and I'm having trouble ratifying in my mind (even with: 'a wizard did it') that the weapon effortlessly passes through things, and yet still damages them without ever loosing energy if what has been changed is that it floats through armour.

Mechanically the problem I have with it is this:

As I understand it the damage of a weapon is a function of it's energy.
The AP rate of a weapon is a function of its ability to assure destructive energy transfer
The HP of an object is a function of it's ability to absorb energy destructively (if that same damage happened multiple times the object would eventually fail)
The DR of an object is a function of its ability to non-destructive absorb energy (if the same non DR defeating damage happened unlimited times the object would still be fine)

so example:

4 guys in full plate stand in a row: Shooter shoots a 2d(200) shot at them.

First guy suffers 2d-1 (-1 damage from going through the full plate) damage; and takes say 8
Second guy suffers 2d-2 (-1 from cover dr of first victim -1 for full plate) damage; and takes say 7
third guy suffers 2d-3 damage; and takes say 6
fourth guy suffers 2d-4 damage; and takes say 5

8p4 = 26; max damage from the pistol is 12; but the spell/imbument/etc is not giving the projectile extra energy it is just making it be a VERY effective penetrator (It basically ALWAYS transfers energy destructively; but it has not gained destructive energy); so my original thought process is that: the hit points of the armour still subtract, but the DR is ignored- the hit points of body armour can be happily ignored since it's fractional (IE the weight of the material that the bullet must travel through is so low that it does not even equate to one hit point when using the weight:dr conversion), but large solid objects in the way still provide some cover because they are massive as well as hard; and then I eye-balled what two meters of stone in a bullet wide tube would have 20 hit points.

So far however this does not seem to be the consensus.

However (Remember the 'wall has 20 hp take that off' was a snap judgement for a scenario I had not foreseen), thinking about this I would postulate a scenario more along the following- the maximum damage that the bullet will cause is 12; it will stop once it has caused that much damage:

First guy suffers 2d-1 (-1 damage from going through the full plate) damage; and takes say 8
Second guy suffers 2d-2[max 4] (-1 from cover dr of first victim -1 for full plate) damage; and takes say 7; which is changed to 4, and the bullet stopped somewhere inside him
third guy suffers nothing
fourth guy suffers nothing

Last edited by starslayer; 01-21-2012 at 11:33 PM.
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Old 01-22-2012, 12:13 AM   #12
Ulzgoroth
 
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Default Re: Cover DR and armour penetration

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Originally Posted by starslayer View Post
Well unfortunately 2d(200) was what I was dealing with because the PC had penetrating strike and was using a pistol and decided to shoot through the wall the enemies were hiding behind. So I'm not using 2d(200) to represent anything, and I'm having trouble ratifying in my mind (even with: 'a wizard did it') that the weapon effortlessly passes through things, and yet still damages them without ever loosing energy if what has been changed is that it floats through armour.
Penetrating Strike is an imbuement?

A wizard did do it. Asking it to play nice with physical logic is ignoring the basic character of the effect.
Quote:
Originally Posted by starslayer View Post
Mechanically the problem I have with it is this:

As I understand it the damage of a weapon is a function of it's energy.
The AP rate of a weapon is a function of its ability to assure destructive energy transfer
The HP of an object is a function of it's ability to absorb energy destructively (if that same damage happened multiple times the object would eventually fail)
The DR of an object is a function of its ability to non-destructive absorb energy (if the same non DR defeating damage happened unlimited times the object would still be fine)
First and most importantly, this is not a mechanical problem. Mechanically, everything is consistent and works fine. You're having trouble with meshing the results of the mechanics with your mental model.

I think, when you get down to it, your understanding has a lot of issues.

Damage as a function of energy? Not even clean for bullets, I don't think, AP bullets aren't lower energy than ball loadings, but get reduced base damage (I think that's done as a way to render a (1.4) AP factor without actually using non-integral AP factors).

Damage * AP factor directly describes how far the weapon penetrates through things...at least, for piercing/impaling damage types. For bullets and Deadliest Spring bows, in a way that seems strongly related to reality. Other damage types and weapons mechanically behave the same way, whether or not that really fits their nature.

DR for armor relates to how much penetrative potential it can stop. DR for objects...yeah, I guess it's how much it can stop without being meaningfully disrupted. It's not a measure of energy stopped, though.

Neither is HP a matter of energy. Just look at bullets, once again! A HP bullet will cause much more HP loss than an AP bullet, even if both have the same energy and neither over-penetrates.
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Old 01-22-2012, 12:42 AM   #13
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Default Re: Cover DR and armour penetration

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Originally Posted by starslayer View Post
Does armour penetration apply to cover DR; or no?
{my edit}
So how should cover DR be handled when armour penetrators are in play?
Basic Set, Campaigns, p408
Quote:
add together the target or cover’s DR – on both sides, for a person in armor – and HP (for flesh), 1/2 HP (for a machine, vehicle, or other Unliving target), or 1/4 HP (for a Homogenous object). Use the object’s DR alone if it’s a thin slab, like a wall or a door. Finally, apply any armor divisor.
DR10, HP400{Hom} gives a cover DR of 110? Versus 2d(200); yes, it's only 1pt of protection but a -2 or -10 to hit.

I wanna play with the 4*man-in-a-can numbers but gotta go walk the dogs:(
{4*DR7+ave10HP+DR7... Rounding 0.1 up to DR1 seems excessive}
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Old 01-22-2012, 01:00 AM   #14
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Default Re: Cover DR and armour penetration

The issue isn't GURPS, which is doing what it's supposed to do, but rather, it's an issue with trying to reconcile a clearly ridiculous result (on that I think we can all agree) with reality. Trying to do that with an effect created by magic is impossible.

Thus, as others have said, logic really can't be applied to it. No actual attack (i.e. one based on reality as we know it) would ever do 2d(200), thus, trying to model the effects of that weapon realistically will result in nonsense.

Anyone remember that old Arnold film, Eraser? They had "x-ray vision scopes" mounted on "railguns" that would shot through basically anything yet stop the instant they hit a human heart and proceed to blow the target several tens of yards backwards and up into the air. For all intents and purposes, that's what you are dealing with here, except your situation actually makes more sense because a wizard literally enchanted the bullet.
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Old 01-22-2012, 07:47 AM   #15
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Default Re: Cover DR and armour penetration

Why are people saying the wall gives DR1? You round down DR with a minimum of zero. In this it highlights the issue even more since you can get really strange results where you fire the bullet through dozens of people without it being affected at all and then it stops inside the target.

This is why things with armor divisors past 10 need to have an established mythology before being used. It's exactly as reasonable for a weapon with an infinite armor divisor to shoot through a planet as it is for it to never overpenetrate.
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Old 01-22-2012, 08:44 AM   #16
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Default Re: Cover DR and armour penetration

Good question - is it because DR0 v's #d(0.#) is DR1? I can't think where to find exemplar for something like 110/200 being 0.
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Old 01-22-2012, 01:53 PM   #17
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Default Re: Cover DR and armour penetration

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Originally Posted by lexington View Post
Why are people saying the wall gives DR1? You round down DR with a minimum of zero. In this it highlights the issue even more since you can get really strange results where you fire the bullet through dozens of people without it being affected at all and then it stops inside the target.
Why would it stop in the target? Unless there's some special rules about Penetrating Strike only acting as an armor divisor until hitting the target, the (200) shot will drill right through the target just as well as it does everybody else.
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Old 01-22-2012, 02:05 PM   #18
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Default Re: Cover DR and armour penetration

Quote:
Originally Posted by Ulzgoroth View Post
Why would it stop in the target? Unless there's some special rules about Penetrating Strike only acting as an armor divisor until hitting the target, the (200) shot will drill right through the target just as well as it does everybody else.
it's an interesting point. The old 3e system - I think (it's been a while) - would divide damage by the armor divisor as well. 4e got rid of that, but unless it literally IS magic (and I think it might be), then the residual energy after going through the target (and delivering 2d worth of tissue disruption) will be nearly unchanged.
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Old 01-22-2012, 02:10 PM   #19
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Default Re: Cover DR and armour penetration

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Originally Posted by Ulzgoroth View Post
Why would it stop in the target? Unless there's some special rules about Penetrating Strike only acting as an armor divisor until hitting the target, the (200) shot will drill right through the target just as well as it does everybody else.
Because it is magic, IMHO. Penetrating Weapon gives an armor divisor. It doesn't reduce the damage. So if it were my campaign, what would happen in the hypothetical four guys in plate mail, the first guy's chest plate would get penetrated like nothing is there, but the projectile would stay in him, because it doesn't have enough damage to punch through the fleshy bits which the magic is not helping it to penetrate.

This does mean, by the way, that you should duck behind a cow. :P

Any non-magical weapon with AD 200 is super-science silly.

The biggest problem for the shooter would be to actually hit something, unless the baddies are a few rows deep pressed against the wall...

EDIT: Hmm. The 3rd ed Grimoire is much less silly, as Penetrating Blade is simply -X DR and PD, rather than a divisor.

Last edited by Whyte; 01-22-2012 at 02:15 PM.
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Old 01-22-2012, 02:15 PM   #20
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Default Re: Cover DR and armour penetration

For over-penetration, I always subtract damage done to the target from the damage total or the attack, no matter what the armor divisor. So line up 3 guys with HP 10 and fire a bullet doing 21 damage with a 200 armor divisor, and it does 10 damage to the first guy, 10 to the second, and 1 to the third. Unless it's some sort of special attack, like radiation or something or a magic deathray. If it's that straight up magical I don't even care about over penetration.

Last edited by Tyneras; 01-22-2012 at 02:20 PM.
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