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thetrav
Thrown grenades almost always end up on the ground before they explode.

The Blast in a confined space rules mention blast waves bouncing off up to 6 surfaces to increase damage.

So my question, is whether grenades should almost always be getting roughly double their damage.

It seems a bit nuts
Yerameyahu
Grenades are dangerous.
Mayhem_2006
"On the ground" is not equal to "in a combined space"
Yerameyahu
It kinda is, especially with the screwy 'reflection' system SR4 uses. Don't forget, though, that you'd have to be standing *directly* over the grenade: in SR4, it's only direct, surface-perpendicular reflections that count. No, it doesn't make any kind of sense, but it's just an RPG, and abstractions have to be made.

*shrug* The correct answer here really doesn't matter at all, because the only important thing is playability. If having double-strength grenades doesn't render them unusably-powerful in your game, enjoy. smile.gif Otherwise, ignore the ground.
KarmaInferno
Well, technically, even in real life military explosive projectiles are sometimes air-burst to take advantage of the ground reflection effect to the blast wave.



-k
Manunancy
My take would be that the reflected blast from the ground is already factored in - wether the grenade exploses directly on the ground or maybe one meter above it with a timed burst won't change things enough to matter. And I'd consider that the 'upward' blast that might be reflected on the ceiling already includes what's being reflected from the floor. The rules don't need an extra layer of complication into the mix.
Yerameyahu
Either way, by the SR4A rules, it only matters if you're *directly* between the bomb and the ground (or ceiling, or wall, and only if they're strong enough to reflect the blast). Which is ridiculous, but there you have it.
AppliedCheese
A quick check on the reality given the nature of what bounces what:

1) The ground is actually an explosion reducer for grenades. Typically it absorbs, rather than reflects, a heaping dose of concussion and shrapnel. Hence why people hit the dirt when artillery/a grenade comes in. Most ordnance that ground bursts ends up creating an "up and out" pattern.

2) Air burst don't try to reflect the concussion off the ground. They, for the most part, rely very little on concussion. They are intended to spray shrapnel in a more even distribution downwards across the target area, thereby negating the disadvantages of an "up and out" ground burst.
DMiller
I created a "Chunky Salsa" calculator (using MS Excel). It's still in testing phase. Please take a look and feel free to send me feedback.

The example loaded is a 2m x 3m jail cell. Target in the NE corner, grenage in the center and the south wall being the more or less "open" end of the cell.

https://www.sugarsync.com/pf/D024671_68_6228651696

-D
Neurosis
For the sake of common sense, I personally would not count the ground.

That's just me.
KarmaInferno
QUOTE (AppliedCheese @ Oct 26 2010, 07:41 PM) *
A quick check on the reality given the nature of what bounces what:

1) The ground is actually an explosion reducer for grenades. Typically it absorbs, rather than reflects, a heaping dose of concussion and shrapnel. Hence why people hit the dirt when artillery/a grenade comes in. Most ordnance that ground bursts ends up creating an "up and out" pattern.

2) Air burst don't try to reflect the concussion off the ground. They, for the most part, rely very little on concussion. They are intended to spray shrapnel in a more even distribution downwards across the target area, thereby negating the disadvantages of an "up and out" ground burst.


That depends.

In a wilderness environment, yes, dirt absorbs some (but not all) of the shockwave. It is likely that the little remaining force that is reflected is negligible as far as damaging effects.

In an urban environment, like most shadowruns take place in, many ground surfaces are rigid enough to create a considerable shockwave reflection.

Ground reflection is enough of a problem that commercial demolition projects need to calculate for it and sometimes damping materials (sandbags, dirtpiles) are strategically located in explosives set-ups to mitigate the issue.

That said, it's probably not worth it to calculate out in Shadowrun most of the time.



-k
Yerameyahu
The rules don't even support it. If you really wanted to, you'd have do it with 3D geometry and precise measurements of surfaces, explosion source, and target locations. Bleh.
Shinobi Killfist
Chunky salsa is one of those rules I hope they either vastly simplify or get rid of whenever SR5 comes out. It is overly complex for virtually no gain in enjoyment.
KarmaInferno
I wouldn't mind if it was just simplified to something like, "if the GM decides the area is sufficiently enclosed and sturdy to create reflecting shockwaves, add a flat X DV to the damage before the resistance test."



-k
Yerameyahu
It has a sort of flashy appeal as a concept, but not as a mechanic. smile.gif It's good for snickering over.

It seems like it'd be (relatively) easy to simplify, too. Instead of calculating multiple reflections, just give +DV for basic increments of confinement? Like, open field, 1-2 walls within X meters, 3-4 walls, complete box… And just assume the ground is always within the blast radius; blasts during aerial dogfights can have a special exception. wink.gif So, 4 basic options for the GM to just eyeball and done?

Edit: Indeed, KarmaInferno.
Shinobi Killfist
QUOTE (KarmaInferno @ Oct 27 2010, 12:10 AM) *
I wouldn't mind if it was just simplified to something like, "if the GM decides the area is sufficiently enclosed and sturdy to create reflecting shockwaves, add a flat X DV to the damage before the resistance test."



-k


That is exactly the type of simplification I was talking about. It is a kind of cool concept, but it has always been both disgustingly abusive and a pain in the ass.
Surukai
My guess is that the floor must be calculated in the damage already. You need 10 kg (40 times the weight of a grenade) to get to 10+P With TNT. (Something is seriously wrong with explosives in SR)
Yerameyahu
Presumably, it's not TNT in the grenades, and who knows how many 'IED net hits' they got, but yes. The inconsistency does annoy. smile.gif
Game2BHappy
This is only an approximation, since it says "for purposes of...", but Arsenal gives an idea of the explosives in grenades:
QUOTE (Arsenal, p.90)
"For purposes of sympathetic detonation, commercial hand grenades contain Rating 8 explosives, their plastic outer shell giving them Armor Rating 2. Mini-grenades, rockets, and missiles use Rating 12 explosives, with an Armor rating of 1."

At R8 you would only need 25% of the mass compared to TNT (which is R4) and I would guess some demolition-ing might go into their manufacture to make the explosives more effective than the base explosive rating would normally be.

Note: I'm not saying the grenade rules mesh anywhere near reality, but the idea of Chunky Salsa Effect has always made me warm and fuzzy inside. smile.gif For my own .02 NuYen, I would consider halving the power of grenades, doubling their range, & then using the ground as a reflective surface to bring the power back to normal. Except ... I haven't had too much in-game issue yet and I don't really like adding too many house rules to my game. Classic CSE for me! wink.gif
Smokeskin
QUOTE (AppliedCheese @ Oct 27 2010, 01:41 AM) *
A quick check on the reality given the nature of what bounces what:

1) The ground is actually an explosion reducer for grenades. Typically it absorbs, rather than reflects, a heaping dose of concussion and shrapnel. Hence why people hit the dirt when artillery/a grenade comes in.


In the army, I was told to hit the ground because you present a much smaller profile to be hit by shrapnel, especially if you can lie down facing the point of impact - and that also lets your helmet cover a lot of the little body you present.

I was also taught to not rest my body to the ground but keep it an inch off and stay on elbows and knees/toes, because the ground could transmit shock waves from artillery and cause internal bleeding.
Smokeskin
QUOTE (Surukai @ Oct 27 2010, 07:10 PM) *
My guess is that the floor must be calculated in the damage already. You need 10 kg (40 times the weight of a grenade) to get to 10+P With TNT. (Something is seriously wrong with explosives in SR)


Explosives aren't that dangerous - sure it can kill you from the blast, but unless you're in direct contact, surprisingly large amounts are needed to kill people. The real danger from hand grenades is in the shrapnel.
KarmaInferno
Yeah, I recall a report of an incident in Iraq where a soldier had a grenade go off nearly point blank.

What saved him was the tip of a buried rock or wall (can't remember exactly) sticking out of the ground a few inches, that happened to be between him and the grenade, providing a tiny cone of hard cover from the shrapnel that by pure chance was just enough to protect his head and vitals since he'd dropped to the ground.

He suffered from the shockwave a major concussion, blown out eardrums, a couple of cracked bones, some shrapnel to his arms and legs, and his body was one giant bruise, but he survived well enough to return to duty a few months later.



-k
Smokeskin
I just remembered we also dug a small 1 foot deep well in the corner of the fox holes, so you could kick grenades into there.
Brainpiercing7.62mm
So what about airbursting directly over someone? I agree it sort of makes sense to factor in the ground as standard, and disregard it, but.... Ideally you then really need to deduct damage for airbursting. Especially as shrapnel in SR is pretty useless for anything except civilian mass murder.

They really should have written something about this.

Another case is actually when the explosion is reflected off the target. Say, you want to blow up a tank. You put a bomb on the ground, the tank drives over it, it explodes. The blast isn't strong enough to penetrate the tank, gets reflected back, hits the ground, gets reflected, and hits the tank again, etc. For destroying barriers you can actually do that. I think noone would want to do it for a vehicle. It is, of course, also not even realistic, as a reflected shockwave might just as well cancel out the original one.
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