GURPS skill used to assemble a bomb?

[HANS]

Originally Posted by Sable Wyvern

My point was a WWI Soldier would not use the Soldier skill to make such a bomb.

Yes. The improvised explosive devices ("jam-tin grenades") used in WWI were, for the most part, not made by the soldiers who used them, but by their mates in the attached combat engineer units, ie, folks who have Explosives (Demolition).

Cheers

HANS

[Kromm]

Originally Posted by jacobmuller

So Explosives (Demolitions) is the skill to set up the classic artillery shell in a culvert IED?

Yes. The way I've always handled that is with a flat -2 for unfamiliarity, removed by a successful Armoury (Heavy Weapons), Engineer (Combat), or Explosives (EOD) roll before the Explosives (Demolition) roll. You don't have to roll twice, but if you're a professional who regularly deals with shells or unexploded ordnance, you'll have a better idea of what to expect.

Originally Posted by jacobmuller

With Camouflage (modified for time) to hide it and you get -2, or use Set Trap, unless you're remote triggering?

That seems fine.

Also, it's important to note that few people doing this are "unskilled," whatever Western propaganda says. These are people trained by "advisors" from local and international groups with political agendas. They definitely have several of the skills above.

[Verjigorm]

What about all manner of improvised explosive devices, the directions for which are included in many field guides? Such as the "eagle cocktail": a thermite grenade, an ammo tin filled with oil/gas mix?

I think soldier could certainly be used to make explosive devices, so long as they fell under the "easy" tasks for Demolitions.

[nanoboy]

I remember reading an army manual about making all manner of improvised explosives and incendiaries. As I understood it, the manual was written for the average infantryman, and I got the impression that if one had the manual handy, it would be easy for someone of average intellect to put the instructions to use.

[Kromm]

There's a huge difference between "use parts like bulk explosive, blasting caps, and batteries (where you must know weights, voltages, sensitivities, etc., and how to tamp, shape, and position charges) to do something specific" and "use a prepacked round of ammunition (grenade, landmine, satchel charge, etc.) in some creative way." Working directly with demolition equipment to manufacture your own munitions is not covered by Soldier; you need Explosives (Demolition) for that, although a good manual might give from +1 to +10 for ease to a specific task, with +5 or better sufficing to allow the average Joe to try. Setting existing munitions is covered by Soldier, provided that it's simple enough that someone with Explosives or Traps would roll at +4 or higher for ease – and that +4 could still come from a manual. For examples, see the rules for deploying landmines (High-Tech, p. 189) and setting grenade traps (High-Tech, p. 190).

And note that not everything is a skill roll. The Molotov cocktail on p. 191 of High-Tech expressly requires no skill roll. Likewise, as p. 24 of Action 2 says, "Anybody can place charges previously rigged with blasting caps or a timer, or push the button on an exploder or a remote."

Some elements in field manuals are instructions that give a bonus to default Explosives. Other bits are instructions intended as part of Soldier training. And still others are pointing out the obvious . . . you don't need to be an elite killer to grasp the concept of lighting a match or pressing a button.

[nanoboy]

Originally Posted by Kromm

Some elements in field manuals are instructions that give a bonus to default Explosives. Other bits are instructions intended as part of Soldier training. And still others are pointing out the obvious . . . you don't need to be an elite killer to grasp the concept of lighting a match or pressing a button.

The thing is that this manual told one how to make thermite and napalm from raw materials. It's been a while, but I think that there were some more complex explosives described, too. It wasn't just taking what you had in your kit and putting it to use (though that was there.) It was taking things that you might find in a modern home and putting them to use. I doubt that this manual was particularly well-distributed, but maybe knowing it might give Perk that lets one use Soldier for improvising a bunch of these things. You're certainly not going to be doing controlled demolitions of a high-rise, but you would be able to make a roadside bomb with it.

[Ulzgoroth]

Originally Posted by nanoboy

The thing is that this manual told one how to make thermite and napalm from raw materials. It's been a while, but I think that there were some more complex explosives described, too. It wasn't just taking what you had in your kit and putting it to use (though that was there.) It was taking things that you might find in a modern home and putting them to use. I doubt that this manual was particularly well-distributed, but maybe knowing it might give Perk that lets one use Soldier for improvising a bunch of these things. You're certainly not going to be doing controlled demolitions of a high-rise, but you would be able to make a roadside bomb with it.

Well, first of all thermite and napalm are probably about the simplest incendiaries that you can make. They're not at all comparable to actual explosives-making or demolitions.

Secondly, it doesn't seem likely that that would extend your Soldier skill, rather than be a manual that tells you how to do the (rather basic) work of making those incendiaries. And maybe gives a bonus to doing so at default, if any skill roll is needed.

[Kromm]

It's crucial to distinguish explosives from incendiaries – and simple mixtures from compounds. Mixing incendiaries (gasoline + thickener, rust + aluminium, etc.) or black powder (closer to being an incendiary in its own right, in fact) isn't in the same league as synthesizing RDX or TNT, cooking nitroglycerin, or trying to make your own lead styphanate. I'd be skeptical of any "field manual" that claimed to teach grunts with no prior laboratory experience how to synthesize explosives. Most likely, it didn't, and was describing home-made incendiaries. Next most likely, it was a manual for specialists; manufacturing explosives from reagents – be they lab-grade chemicals or household ones – isn't something you tell someone who lacks suitable training to go do, unless your goal is to get him killed. Which suggests a third possibility: It wasn't a true field manual, but one of those anarchist/survivalist publications done up to resemble one, in which case all bets are off.

I would still apply the principles I outlined earlier: You need Chemistry to create the stuff, but a good manual gives a bonus. The problem is that the bonus won't be large enough to overcome the -6 to IQ for the Chemistry default, let alone the -2 or worse for sensitive substances like nitroglycerin, azides, fulminates, and styphanates. I'd even be mean and say that those working by default must treat any failure as critical failure, however good the manual. That's because no manual designed to be rolled up and carried in the field will be able to provide the grasp of theory and the experience with safety needed to do this sort of thing with any reliability.

[nanoboy]

Yeah, I wish I still had access to the little thing, but I borrowed it from a friend in high school, so it's long gone. I remember it had some explosives manufacturing in it-- again, nothing as complex as military grade high explosives, but there were explosives recipes there. Some of them were fairly involved and would require a pretty well-equipped kitchen and garage. My point, though, is that modern militaries train some soldiers in such things, even if they aren't explicitly combat engineers.

[Sable Wyvern]

Originally Posted by nanoboy

Yeah, I wish I still had access to the little thing, but I borrowed it from a friend in high school, so it's long gone. I remember it had some explosives manufacturing in it-- again, nothing as complex as military grade high explosives, but there were explosives recipes there. Some of them were fairly involved and would require a pretty well-equipped kitchen and garage. My point, though, is that modern militaries train some soldiers in such things, even if they aren't explicitly combat engineers.

I can't imagine any sane military issuing this sort of manual to the average infantry soldier.

The Australian Army actually stopped including the booby-trapping section in most copies of their mine warfare manual, and only issues the complete version under much stricter security.

While I'm not entirely convinced this should have been done, anything teaching the creation of explosives from scratch is so dangerous and open to abuse I just can't see it being a widely circulated manual. Especially considering that anything requiring "a pretty well-equipped kitchen" is going to be useless to a soldier in the field.

I agree entirely with Kromm's three possiblities -- either this was a specialist manual, not something designed for issue to the average soldier; it was not an official military manual at all; or your recollection is mistaken.

As an additional data point, Australian assault pioneers (infantry combat construction and assault demolition specialists) receive no official training on the creation of explosives.