OK, i gotta admit, I'm rather stymied by all of this explosives stuff. I feel sorta like when you play someone elses game of minecraft and you get the basics of the game, but you don't know what all their mods do, y'know? If there's anyone in the group that gets this stuff and wouldnt mind giving me a crash course in explosives 101, or a link to a quick and easy guide of the basics, that would be AWESOME. i don't wanna hold the game up over this any more than i feel like i already have been.
Keeping it simple, explosives boils down to two things that matter: Rating and Kilograms. The final DV of your boom is determined by the Rating multiplied by the square root of the kilograms used. For simplicity, never bother with a number of kilograms that does not have a whole number as the square root. Here's a handy table.
Kilograms | Multiplier |
1 | 1 |
4 | 2 |
9 | 3 |
16 | 4 |
25 | 5 |
Etc.
There are two tests when building a bomb. The first is to shape the explosive and make it better at booming, increasing the effective rating. This is optional, and is the test described in the core book. You roll Logic + Demolitions, and add your hits to the rating of the bomb when determining DV.
The second test is the actual construction of the bomb. Since this is the Simple version of building a bomb, the time is entirely dependent on how many kilos you plan to use. (There are other factors, like number of charges/detonators, but you don't need to worry about that.)
Simple: 5 kilograms or less. Demolitions + Logic [Mental] (6, 10 minutes) Extended Test.
Average: 6-10 kilograms. Demolitions + Logic [Mental] (12, 1 hour) Extended Test.
Complex: 11 kilograms or more. Demolitions + Logic [Mental] (18, 1 day) Extended Test.
So you decide you want to build a 4 kilogram bomb out of the 4 sticks of dynamite you have.
Step 1: Logic + Demolitions [Mental] Simple test. You get 2 hits, so your Dynamite sticks now count as rating 7. (5 + 2 hits).
Step 2: Build the bomb. It's less than 5 kilograms, so this is a Demolitions + Logic [Mental] (6, 10 minutes) Extended Test. You easily combine your dynamite with detonators in about 30 minutes.
4 kilograms is a x2 modifier, so your bomb is 14P, AP -2, with a Blast of -2 per meter.
You get a bonus if you attach it directly to a structure. This both doubles the DV and halves the armor value of the barrier. In this situation, your bomb is 28P AP -half, Blast -2 per meter. This bonus only applies to the Structure. Anything else caught in the blast takes the base damage. The shrapnel created by destroying the Structure is a different matter.
And that's all you really need to know for the basic level of bomb making. You can get more complicated by involving the different detonators, tamping, multiple charges, Homemade explosives, including Anti-Removal modifications, breaching vs. cutting charges, using explosives purely to create secondary sharpnel blasts, abusing enclosed spaces to achieve chunky salsa, and so on, but you can work your way up to all that.
And I imagine Tecumseh would include a third test for setting up a fancy booby trap using the bomb you just built, like the one mentioned with Grenades. That gets into Build/Repair territory, where the only limits are your imagination and the leniency of the GM.