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Old 07-13-2010, 01:15 AM   #1
RogerBW
 
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Default Limpet mine damage

Short version: do ULTRA-TECH limpet mines always do maximum rollable damage?

There's some precedent for this - the Contact Explosions rule on B415, HIGH-TECH's extrudable and foam explosives, cutting cord and detcord (all p.187).

Against this, there's B414 ('the listed damage applies only applies "as-is" to the target struck' when shooting at people with explosive attacks), the fact that Internal Explosions (B415) do not maximise damage, and the inconvenient fact that e.g HEAT warheads do need to detonate at a slight distance from the target to have maximum effect. And of course that it's not specified in ULTRA-TECH.

So is there any chance of an official ruling on this?
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Old 07-13-2010, 02:17 AM   #2
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Default Re: Limpet mine damage

Quote:
Originally Posted by RogerBW View Post
Short version: do ULTRA-TECH limpet mines always do maximum rollable damage?

There's some precedent for this - the Contact Explosions rule on B415, HIGH-TECH's extrudable and foam explosives, cutting cord and detcord (all p.187).
I don't see how a stuck-on, explosive limpet mine can avoid being a contact explosion for maximum damage.

HEAT needs a stand off distance for best performance of the narrow penetrating jet. In all other directions, it does much less damage at a distance than in contact.

http://en.wikipedia.org/wiki/High_ex...i-tank_warhead

EDIT: Better article http://en.wikipedia.org/wiki/Shaped_charge
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Old 07-13-2010, 05:13 AM   #3
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Default Re: Limpet mine damage

While I can see that a contact explosion should do a lot of damage, having it do the maximum possible strikes me as a bit extreme. It would certainly tend to make limpet mines into very scary weapons indeed (and inspire designs for Transhuman Space weapon systems consisting of medium-speed cybershells flying up to opponents and sticking limpet mines on them, because that's far deadlier than, umm, shooting someone with the same explosive shell). I tend to interpret that rule as being specific to characters heroically throwing themselves on top of a grenade and enclosing the entire blast to save their friends; the trick will only work if the charge is completely enclosed by the victim, and anyway, it's supposed to be a suicidally heroic gesture, damnit.
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Old 07-13-2010, 06:24 AM   #4
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Default Re: Limpet mine damage

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Originally Posted by Phil Masters View Post
While I can see that a contact explosion should do a lot of damage, having it do the maximum possible strikes me as a bit extreme. It would certainly tend to make limpet mines into very scary weapons indeed (and inspire designs for Transhuman Space weapon systems consisting of medium-speed cybershells flying up to opponents and sticking limpet mines on them, because that's far deadlier than, umm, shooting someone with the same explosive shell). I tend to interpret that rule as being specific to characters heroically throwing themselves on top of a grenade and enclosing the entire blast to save their friends; the trick will only work if the charge is completely enclosed by the victim, and anyway, it's supposed to be a suicidally heroic gesture, damnit.
That's true, but it says "contact" rather than "well tamped between a human
body and the floor".

I'm not sure it's a valid to compare a limpet mine with an explosive shell. The manual placement lets you devote all resources to maximum damage in a fixed relative direction, while a shell has handle firing stresses and unknown angle of incidence. Isn't there a trick where you can give a satchel charge a metal backing to reflect some of the outward shockwave back into the target?

And I'd much rather be waylaid by cybershells that have to slow down and place a limpet mine on me so I can shoot them down, than to have one shower me with just the grenades at high speed from somewhere out of LOS, unable to return direct fire.
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Old 07-13-2010, 08:27 AM   #5
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Default Re: Limpet mine damage

Random damage dependent upon margin of success of mine placer to reflect location of emplacement, ie you can choose wear to stick it and might roll a critical.

re HEAT stand-off distance: it's built into the warhead, see magnetic grenades from WWII or look at the shape of a shaped charge warhead.
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Old 07-13-2010, 09:35 AM   #6
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Default Re: Limpet mine damage

Quote:
Originally Posted by RogerBW View Post
Short version: do ULTRA-TECH limpet mines always do maximum rollable damage?

There's some precedent for this - the Contact Explosions rule on B415, HIGH-TECH's extrudable and foam explosives, cutting cord and detcord (all p.187).

Against this, there's B414 ('the listed damage applies only applies "as-is" to the target struck' when shooting at people with explosive attacks), the fact that Internal Explosions (B415) do not maximise damage, and the inconvenient fact that e.g HEAT warheads do need to detonate at a slight distance from the target to have maximum effect. And of course that it's not specified in ULTRA-TECH.

So is there any chance of an official ruling on this?
No official ruling but just my opinion...

The considerations about HEAT are not really relevant. One can have contact explosions with any other form of explosive warhead.

The consideration about "as is" damage explains the difference between being hit by the explosive round, and being caught in the blast area. Note that if one is hit by an explosive round which has an impact fuse, that _is_ a contact explosion.

The occurrence described in the box on p. B415 is titled "Contact Explosions", but IMHO it covers only a very specific case - as already mentioned by Phil Masters.
Note by contrast that if the same hand grenade explodes as thrown, directly in contact with the torso of the target, it will do damage "as is", not maximum possible. And it stands to reason, because the explosion will have effect in every possible direction - including away from the target's torso.
We know that in the case described in the box _all_ damage goes against the heroic soldier: we know that not only because he gets maximum damage, but also because everyone else gets protection from his DR and, well, body parts (yeesh). Not so in the case of a contact explosion described on the previous page; the guy hit gets damage "as is", and everyone else in the blast are may receive collateral damage, gaining no protection from the target.

Sure there are shaped charges and other forms of directed blast, which minimize the amount of force wasted in other directions but the useful one - but that is usually taken care of by way of armor divisors.

Just my opinion.
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Old 07-13-2010, 11:44 AM   #7
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Default Re: Limpet mine damage

Quote:
Originally Posted by RogerBW
Short version: do ULTRA-TECH limpet mines always do maximum rollable damage?

There's some precedent for this - the Contact Explosions rule on B415, HIGH-TECH's extrudable and foam explosives, cutting cord and detcord (all p.187).

Against this, there's B414 ('the listed damage applies only applies "as-is" to the target struck' when shooting at people with explosive attacks), the fact that Internal Explosions (B415) do not maximise damage, and the inconvenient fact that e.g HEAT warheads do need to detonate at a slight distance from the target to have maximum effect. And of course that it's not specified in ULTRA-TECH.
I do not think the mines are intended to do maximum damage, for reasons pointed out by yourself, Phil, and Michele.

Regarding the High-Tech cites: I believe the intention of the two mold-able TL8 types is that the higher damage comes (at least in part) from being designed to fit into cracks and similar small openings, where less of the explosive force is wasted. Detcord benefits from being wrapped around something, rather than merely being placed on it, and cutting cord is a type of shaped charge.
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Old 07-13-2010, 12:52 PM   #8
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Default Re: Limpet mine damage

Quote:
Originally Posted by Not another shrubbery View Post

I do not think the mines are intended to do maximum damage, for reasons pointed out by yourself, Phil, and Michele.
That is correct. "Maximum possible damage" is for contained explosions. Merely touching the explosive isn't enough (although that'll still mean the full damage roll with no attenuation for distance, which can be rather bad). Now a land mine (not limpet mine) fully in contact with the ground below and a vehicle above definitely would do maximum damage . . .

Quote:
Originally Posted by Not another shrubbery View Post

Regarding the High-Tech cites: I believe the intention of the two mold-able TL8 types is that the higher damage comes (at least in part) from being designed to fit into cracks and similar small openings, where less of the explosive force is wasted. Detcord benefits from being wrapped around something, rather than merely being placed on it, and cutting cord is a type of shaped charge.
Extrudable explosive is squirted into gaps like caulk, while foam explosive is injected from a pressurized dispenser; both measures are expressly to ensure that the blast is "contained" for maximum effect. As for det cord and cutting cord, careful wrapping is considered just as good for this effect. All of these examples are expressly cases of skillful application of demolition explosives out of combat by somebody using Explosives (Demolition).

At any rate, do note the progression:
  • At distance: Damage is ×1, divided by (10 × distance in yards) in vacuum, (3 × distance in yards) in air, (2 × distance in yards) for FAE in air, or (distance in yards) in water. Use this for distant combat explosions.
  • At touch on exterior: Damage is ×1. Use this for direct hits in combat.
  • Tamped or shaped on exterior (High-Tech, pp. 182-183): Halves explosive weight needed. Effectively, damage is ×1.4. Use this for most demolition.
  • Fully contained on exterior (p. B415): Maximum damage. Effectively, damage is ×1.7. Use this for demolition where explosive is in gap or applied over full surface of object.
  • Internal (p. B415): Wounding, and effectively damage, is ×3. Use this for explosive bullets in flesh, for instance. In the head (e.g., cyberpunk brain-bombs), use ×4! For targets with No Vitals or Homogenous, treat as tamped (×1.4) only.
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Old 07-13-2010, 01:56 PM   #9
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Default Re: Limpet mine damage

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Originally Posted by Kromm View Post
  • Internal (p. B415): Wounding, and effectively damage, is ×3. Use this for explosive bullets in flesh, cyberpunk brain-bombs, etc.
Wait...does that mean that a brain-bomb does x3 rather than the normal brain x4? (The x3 is characterized as relating to the Vitals hit location on B415, I think.) Or that it does x3*x4 for x12?

Also, does this ever apply to unliving or homogeneous targets?
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Old 07-13-2010, 02:05 PM   #10
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Default Re: Limpet mine damage

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Originally Posted by Kromm View Post
[*]Internal (p. B415): Wounding, and effectively damage, is ×3. Use this for explosive bullets in flesh, cyberpunk brain-bombs, etc.[/list]
Does this also assume that the damage is maximized, for max x3 damage?

After all, if jumping over a grenade and covering with your body means that you take maximum damage, having one explode in your guts out to have the same effect, plus the vitals multiplier...
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