[DoubleTap]

A little back ground here my real world job for the last 10+ years involves Jumping from plane, rappelling down helicopters, and mountains.  Using a variety of automatic weapons , for several different countries, and of course rigging explosives, and disarming land mines.   I also have some training in using explosives to do "Dynamic" entry into buildings.   

So in the game last night one of my players, want to use 3 pounds of C-4 to blow a hole in a vault.  The argument came about that I pointed out NO way in hell are you making a hole big enough in a vault to get through with 3 piddly pounds of C.  By the explosive rules in arsenal, as long as you beat the barrier rating, you can.  I hate the GM hammer method, and don't use it.  I'm also not a rules lawyer either, so any suggestions on how to settle this fairly?  I'm also good about letting my players use there knowledge on subject to enhance the game.  One of them Installs alarm systems, some of them very run of the mill, and some high end, so I usally differ to his knowledge on the subject when it comes to bypassing that stuff. 
So one aggain the heart of the post is what is a fair way to settle this argument?

[CitizenJoe]

Shadowrun uses kilograms, which is more than twice as much pounds.  Shadowrun also uses C-6(?) and C-12(?) instead of C-4, which are more destructive.  As you can probably attest, placement and conditions are going to have much more effect than mass of explosives.  If you put a water jacket behind the charge, it will direct a lot more of the effect inward, ala chunky salsa effect.  Likewise, boring holes and packing the charges into those is very effective as well. 

Anyway, there are tons of ways to explain away the issue, from simple units conversion error to using the wrong type of explosive to inefficient usage and even blast shielding on the building itself.  If it helps you sleep, imagine that their explosives come from the company Seefoe and the explosives they have does what it says on the can, and isn't actually C-4... it is Seefoe brand plastic explosive rating X.

[CanRay]

I have to be careful with my explosives knowledge, just like my firearms knowledge is scares people in Winnipeg. 

[DoubleTap]

Thanks for the insight canray, and I already told him this.  yes placemnt, tamping, and shaping all effects your net effect with explosives.  still 3 kilos of C is not going to crack a vault big enough to crawl through,  now if you packed it into a shape charge, you get a nice hole, but Not something big enough to get to the loot.

[CanRay]

Thanks for the insight canray, and I already told him this.  yes placemnt, tamping, and shaping all effects your net effect with explosives.  still 3 kilos of C is not going to crack a vault big enough to crawl through,  now if you packed it into a shape charge, you get a nice hole, but Not something big enough to get to the loot.

No, but you'd have a nice cut hole for a better breaching charge.  This is how it's sometimes done in the mines.

[The Big Peat]

My suggestion; tell them how much they'd need, retcon they brought that much, blow the hole in it. In future, everytime they buy explosive, be explicit how about much they can expect it to do and not do. That, or write up new demolitions rules, and pass them to them to use.

[CitizenJoe]

Maybe you're not explaining what a vault is well enough.  The barrier ratings include an armor rating which should be on the order of 32+ for a vault plus structural rating.  These numbers are for 'destroying' a 1 meter square x 10 cm thick barrier.  That's only like 3" thick.  Assuming they meant 3 kg, that's almost 7 lbs of C4.  And they're again probably meaning plastic explosives of varying rating between 4 and 15.  Assuming 4, as in C4, that's a strength of sqrt(3)x4 or 7.  I'm going to assume that a vault is heavily reinforced concrete.  Which is armor value 16 and 15 structure.  At DV 7, sticking it right to the wall to cut armor value in half, it is still just going to blow off the paint.  A typical vault though is likely to be 2 feet thick of concrete which puts its structural value at 120.  The bank door is like a foot thick steel, which has an armor rating in excess of 32.  So you'd need over 16 DV to even scratch it and then you need to punch through over 68 (probably closer to a hundred) in order to get through.  Ballpark figure, you need about 100 DV to punch through the door and 128 to punch through the wall.  That's 45 kg of the best plastic explosive they got (rating 15), or 625 kg of C4.  Note that the bad thing here is the effects of the blast outside of the vault.  That 100 DV drops off at 2 per meter so a serious kill zone out to like 40 meters or so. 

I'm sure some of my number are off here and there, but 3 kg isn't going to touch a vault.

[DoubleTap]

Maybe you're not explaining what a vault is well enough.  The barrier ratings include an armor rating which should be on the order of 32+ for a vault plus structural rating.  These numbers are for 'destroying' a 1 meter square x 10 cm thick barrier.  That's only like 3" thick.  Assuming they meant 3 kg, that's almost 7 lbs of C4.  And they're again probably meaning plastic explosives of varying rating between 4 and 15.  Assuming 4, as in C4, that's a strength of sqrt(3)x4 or 7.  I'm going to assume that a vault is heavily reinforced concrete.  Which is armor value 16 and 15 structure.  At DV 7, sticking it right to the wall to cut armor value in half, it is still just going to blow off the paint.  A typical vault though is likely to be 2 feet thick of concrete which puts its structural value at 120.  The bank door is like a foot thick steel, which has an armor rating in excess of 32.  So you'd need over 16 DV to even scratch it and then you need to punch through over 68 (probably closer to a hundred) in order to get through.  Ballpark figure, you need about 100 DV to punch through the door and 128 to punch through the wall.  That's 45 kg of the best plastic explosive they got (rating 15), or 625 kg of C4.  Note that the bad thing here is the effects of the blast outside of the vault.  That 100 DV drops off at 2 per meter so a serious kill zone out to like 40 meters or so. 

I'm sure some of my number are off here and there, but 3 kg isn't going to touch a vault.

My point exactly Joe.  even if you went for the door, setting up as a liner steel cutting charge, 3kg is not going to do anything. 

[CitizenJoe]

Wait, did they change the rules in Arsenal?  Or introduce a 'vault' as secure as a piggy bank?  Because by the basic rules, you wouldn't even scratch the paint.

[CanRay]

Wait, did they change the rules in Arsenal?  Or introduce a 'vault' as secure as a piggy bank?  Because by the basic rules, you wouldn't even scratch the paint.

That's why you steal the whole vault and drag it Extraterritorial. 

[Ryo]

Having double checked the rules, they calculate the hole you put in the wall using the equation (((square root of 3)*explosive rating*placement modifier) - (Barrier Armor/4))/Base Barrier Structure.

The first part is the DV of the boom. Square root of 3*rating 4*2 for proper placement, would make it 14 DV. Then this DV is reduced by the hits on the Barrier's damage resistance test, so buying hits, that's Armor/4. A vault is surely going to count as Hardened Material, so that's 32 armor, for 8 automatic hits, dropping the DV down to 6.

The remaining DV is then divided by the Base Barrier Structure, which is where the rules probably take liberties with reality. Even though a bank vault is easily a meter thick, you still calculate the structure based on the 1 meter x 10 cm thickness of the barrier table.

DV is now 6, and the structure rating for Hardened is 17, so that's 6/17 for a 0.35 meter hole in the door. Of course, a bank vault would be over a meter thick, so that doesn't come close to getting all the way through, but it's still a way bigger hole than it has any right to be.

This assumes they placed the explosive off the ground for the x2 multiplier. Had they not, their 7 DV base wouldn't even scratch the vault. But if they managed to Tamp it as well for x3 (though they'd need to find something with 16 Armor to do so) they'd get a hole 0.76 meters wide. Still not all the way through, but still surprising for only 3 kilos.

Even by the rules in arsenal, 3 kilos of C-4 won't get a hole all the way through the wall. With only 3 kilos, they'd need at least rating 5 explosives and an x3 multiplier. If they're only getting x2, they would need at least Rating 8.

So you were well within your right to call bullshit on getting all the way through, though they would have made a significant dent.

[Zilfer]

Sounds like it's time to throw an acid ball at the sucker! XD

I have learned something new from this topic, i didn't know vaults were that darn thick! o.o

[CanRay]

Sounds like it's time to throw an acid ball at the sucker! XD

I have learned something new from this topic, i didn't know vaults were that darn thick! o.o

Depends on the vault.

I've heard of some "Vaults" in the US that were just sheet metal riveted to the walls, with the rivets hidden.  Giving the appearance that it's a big vault when really it's Plywood and Sheet Metal, with an impressive door.

[Critias]

The key to using OOC info, whether as a player or GM, is to try to blend it with the "IC info" (IE, the stats and skills a given character's got on his sheet, and whatever rules quirks make the game universe work a certain way).  So in the real world, 3 kilos of C4 isn't gonna blow the door off a vault of any respectable size.  But things to take into account are (a) maybe C12 is super mega awesome compared to C4, (b) the player, if he was buying C12 to take off a vault door, should've known how much to buy if he's got the appropriate skill (so that if C12 isn't super mega awesome compared to C4, if that character's got a decent Demo skill he should have known that from the get-go), (c) if the in-game math still adds up so that the player rolls really well and it should be able to work, the GM should try and find some way to roll with it, because Shadowrun is a game, first and foremost.  So maybe he doesn't have enough C12 to blast right into the vault itself, the hard way, but if the GM is stuck between the rock of "real world doesn't work like that" and the hard place of "but in-game this should be working, and the player planned for in-game, not real-life," I think they should also err on the side of "fuck it, in-game wins if that keeps the story alive."  So maybe he can't blow a hole in the door, but the GM lets the blast take out the locking mechanism and the door swings open as the smoke clears, or something cinematic and goofy like that.

Don't punish players for playing by the rules of the game, basically, is what it boils down to.  If the rules say that X does Y, so the player buys enough X to think he can take care of Y when it comes up...suddenly throwing those game rules out the window, and accidentally making X suck and Y insurmountable, is an error on the GM's part, in my opinion.  House rules are all well and good, but they shouldn't come up in the middle of a game in order to stifle a player's progress, or if they do come up, players should be able to handwave right back -- if the GM says it takes more than 3 kilos of explosive to blast a door, the player should be able to say "well, here's some extra nuyen off my sheet, my character should have known that and would have brought more."

In my opinion, at least.

[Crimsondude]

Don't punish players for playing by the rules of the game, basically, is what it boils down to.  If the rules say that X does Y, so the player buys enough X to think he can take care of Y when it comes up...suddenly throwing those game rules out the window, and accidentally making X suck and Y insurmountable, is an error on the GM's part, in my opinion.

I cannot support this enough.

"The rules don't make sense compared to what I know IRL" is what gave us unplayable Matrix and the Manuever Score. It's a game. Just have fun and roll with it.