Just a curiosity, are there rules for what happens (if anything) to people inside a vehicle that is hit by a concussion grenade?

I'm not aware of explicit rules but I adjudicated it once for a game. The PC was very happy his vehicle wasn't armored so the windows blew out before the concussion grenade could stage up to chunky salsa levels.

Note that in this case the grenade was inside (fired through a window by a grenade launcher).
The shot before that was outside the car and did no damage but would have force da crash check if they were moving.

Very nice, i would be interested in seeing how you worked that, and I'm also trying to figure out how one detonating OUTSIDE would work. i.e. , driving along in your armored ares van and BOOM, a C Grenade goes off in front of or right under you. I would think it would do SOMETHING to those inside.

Are there even Concussion grenades in SR? I can't find any in the list in Arsenal.

If you are talking about a flashbang, the targets inside a vehicle would IMHO at best get the dice pool modifier for the glare, if the flashbang detonated outside the vehicle. Detonating such a grenade inside the vehicle will cause 6S+"Chunky Salsa" as the walls of the car will automatically withstand stun damage.

Very good point, i dont know if C grenades are there or not, ill have to check my arsenal when i get home. I agree that a flashbang isnt going to do much to an armored vehicle unless its inside. And a frag grenade isnt going to do much to an armored vehicle...period..hmm

I know concussion grenades used to exist ( they are specifically mentioned in Brainscan), not sure if they still do.

A Flash-Bang is a type of concussion grenade (that's the bang part).
There are were other types mentioned in earlier SR versions (rubber balls instead of schrapnel) but they're not in base book SR4A. They might be in Arsenal? Basic idea was one of the normal grenade types but stun instead of physical.

If such a thing existed, I'd expect it to do nothing when exploding outside the vehicle. The basic rules for this are kinda dumb: IIRC, any such area attack hits the vehicle and all passengers… but they should benefit from the vehicle.

yeah thats kinda what i thought, they shouldnt really get to messed up unless the armor is exceeded. However, I have been in a tank when an explosion was set off right outside it (yeah yeah, i know, bringing "realism" into it) and you arent happy when that thing goes off. im thinking of applying a penalty slightly akin to a flash grenade, simply due to sound, etc

This is true... While it may not actually damage occupants, the explosion right outside is very unpleasant.

So i think what Im going to end up doing is applying a -2 to physical DP, and a -4 to hearing based perception for 1-3 combat turns.

My thoughts on this are as follows;

1) your going to be disoriented, even if you take no damage, simply from the boom.
2) as a combat turn is 3 seconds then 3-9 seconds of negs doesnt seem to horrible.
3) i think the -4 to hearing based perception checks speaks for itself


comments, questions, concerns?

I think the nature of any penalty should be based on the vehicle (i.e tied to body/armor of the vehicle). Having a grenade detonate outside of your Ford Americar would be very different than if it exploded outside of your Stonewall MBT.

Perhaps allow the vehicles body/armor to add to the player's stats for resisting the effects?

A concusion grenade, IMO, wouldn't have much of an effect on those inside of an enclosed vehicle, unless the blast breached the windows. The concussion part is the blast (overpressure) slamming into you (causing ringing in the ears and disorientation as it runs amok amongst your eardrums and inner ear, and causing concussions/contusions from secondary and tertiary impacts). I'd think most cars would easily enough reflect any blast wave, though windows and fragile parts would be blown out.

Concussion grenades are just frag grenades without the fragmentation. They're mostly effective in enclosed places; using them outside the vehicle I'd warrent greatly reduces their effectiveness.

That sir sounds entirely too reasonable.

But really, that sounds like a good way of handling it. Perhaps you could also for force a composure test or something akin to electrical damage test in order to act within that same round due to the disorientation...Which is something I think flashbangs need in general...

Yeah sorry, my thoughts tangent a bit without my typing following, i went from C grenades to general explosions out side of vehicles, and the penelties i had listed are in the case that the explosion does not breach the armor, thus no ACTUAL damage, but still disconcerting.

And I like the idea of a composure test, hell...if your driving along and grenades start falling around you like rain, your armored up van might be fine, but i bet your gonna need a new pair of shorts!

Depends upon how much faith you have in your armored vehicle.
Generally, the explosion that penetrates is the one that maims/kills you, in a combat environment. So you either trust it (and ride) or you don't (and you use your black cadillacs). Over time, you really just quit caring much. Wastes too much energy on something you have absolutely no control over. *shrug*

Are we talking about Stun Grenades (to be found in SR4a) here? I was always amused how little they can do to vehicles, even drones. I'm actually thinking of outfitting combat drones with a wifi-capable stun grenade each for the occasional close combat.
This aside, a crash test might be appropriate, yeah. A temporay penalty to some sensor checks might come in realistic, depending on the sensors, of course - radar might not care much about some wuzzy bang and a flash of light
If the blast doesn't get inside the (armored) vehicle, it shouldn't have much effect, I'd say.