Hey, Im trying to create an extremely difficult engagement for my Hunter-killer group by throwing them up against some Battlewagons with killkannons in a cramped urban environment. Killcannons have concussive (3) , so im wondering how you would go about resolving this against the crew, what im thinking of doing is reducing the level of concussive by 1 for every 10 armour on the facing hit so the blast would have concusive (0), stunning for 1 round only (instead of d5), on the front of their hellhound.

So does this sound fair enough? Them fighting a superior opponent isnt meant to be fair!

I'm not sure if Concussive is supposed to affect the crew. Though I also thought about this. My solution would be to add the armour value (after penetration) as a bonus to the toughness test.

Though the real question is if concussive should apply to tank crew. After all there's critical damage results that reflect the crew being stunned and if you allow Concussive to work against tanks equiping your infantry with Power Mauls would be a great way of dealing with tanks. Just run up and bash the tank to stun the crew.

I see your point but in that case I dont think it would be to bad if I said that damage has to be done in order for the concussive to apply, that way the SB of the guy attacking with a power maul has to be pretty impressive. As to the righteous fury/ critical damage that stuns the crew I was going to have that in addtion (it creates a high probability of stunning I know, but I guess this just reflects the nature of that particular attack)

This any better?

So: If an attack with concussive(x) damages a vehicle everyone inside the vehicle needs to test toughness as per the normal Concussive rules. Maybe with a bonus to the test based on the vehicle armour.

This might work. Please post how it turns out in the end and if you notice more stuns than you expected or less.

maverick935 said:

I'm not sure if it's that much better. In theory, a couple of righteous furies can have an average mook causing some concussive damage. I would suggest limiting this ability only to Heavy hand-held weaponry and vehicle weapons can cause Concussive damage. As for the method of dealing with the Concussive Toughness Test, I would prefer a bonus to the test provided via armor rating (probably after the armor is reduced by Pen). Whether this bonus is a straight add-on from the armor value or some other method, I'm not too sure. Please report back your findings!

I think your overthinking this a little, out of all th melee weapons in Only War, only one fairly uncommon weapon which has to be specifically weilded and involve scoring a rightious fury causes concussion; keep in mind you also havr to get into close combat with a vehicle in the first place to use it. Really vehicles are tough enough as they are so being able to stun the crew (and get stunned in return) without penetrating the armor seems totally realistic

I'd question the 'realism' of Concussive weapons affecting the crew; I've read plenty of accounts from WWII tank crews who survived their tanks being knocked out by 88mm AT rounds and exploding 6 seconds later. For that matter, I've seen the frame-by-frame footage of a Panther crew bailing out within 5 seconds of their tank being knocked out - it bursts into flames at 6 seconds. While they would certainly be in shock, they clearly weren't Stunned.

I say no to Concussive carrying through; RF already handles such affects handily, and it underscores the toughness of the tank and the importance of keeping it in one piece. Open-Topped vehicles are another matter.

Plasmafest said:

Well just because a weapon is concussive doesn't meant that it will stun. That Panther crew just made their toughness saves.

I'm having conflicting opinions about concussive vs. RF. With the Only War rules you can only get the RF minicrit if you actually deal damage to the vehicle but at the same time I could imagine a hit that shakes the tank around which might cause some of the crew to be stunned without causing any significant damage to the vehicle itself.

If anything I'd make them do the toughness test and if they fail apply the effects of fatigue for a number of rounds instead of being stunned.

I'm just taking a quick stab at this…

For every full 10 points of armour on the facing that was hit, reduce the Concussive (X) rating by -1. The Concussive rating may drop to zero or lower, or it may go higher than its original rating score, but this just reflects the modifier to the Toughness/Operate Test to avoid crew members being Stunned/Fatigued.

A Battle Cannon (Concussive [3]) hits a Leman Russ bang-on from the front (armour 40); Concussive (3) drops to Concussive (-1), meaning the Toughness Test is Ordinary (+10). A hit against the side armour (32) would make the Toguhness Challenging (+/-0). A Hunting Lance (Concussive [2]), using the front armour example above, would become Concussive (-2), meaning the Toughness Test is Routine (+20).

Using an Astartes Thunder Hammer (Concussive [4]) on the front of a Leman Russ would still leave the crew making Challenging Toughness Tests to avoid being Stunned.

(RAW) Critical Damage of 1 either Stuns or causes Fatigue, depending on the location suffering the hit. Stunning effects to Weapon, Turret, or Hull only last one (1) Round, while the Fatigue is 1 Level only if the Operator fails a Challenging (+/-0) Operate Test. Let's just apply the Test modifier to the Operate Tests the same as we do Toughness Tests.

For the purposes of applying the Concussive Quality to vehicles, the following four vehicle Traits might be considered:

• Open Topped Crew of Open-Topped vehicles may be targeted separate from their vehicle by attackers making use of the Called Shot Action (which may be punishment enough). Unless an Open-Topped vehicle is also Ramshackle, I'd say apply the Concussive Quality as outlined above.
• Ramshackle These vehicles are of dodgy construction, so perhaps the Concussive rating is increased by +1 when used against these vehicles.
• Reinforced Armour This is like the vehicle version of True Grit. Vehicles with this Trait reduce the Concussive rating by -1.
• Super-Heavy Due to their immense size and mass, these vehicles reduce the Concussive rating by -3

So we know what modifiers to apply.

Now, when to apply the Concussive Quality to vehicles?

When striking/shooting a vehicle with a weapon with the Concussive Quality, any to-hit roll equal to or less than the wielder's WS/BS Bonus times the Concussive rating has a chance to Stun the crew (as detailed above); these numbers are easy to find and multiply. WS 4 times Concussive (2) = 8% or less on the to-hit roll. Then, if Righteous Fury is generated, the crew must Test vs Toughness/Operate as appropriate (with Weapon, Turret, and Hull being Stunned for 1 Round, or the Operator suffering 1 Level of Fatigue in the case of the motive system being hit.

An ideal scenario: WS Bonus 7 Gunner shooting an Earthsahaker Cannon (Concussive [5]), hits a Ramshackle Munitorum truck in the rear (Armour 10), needs a 35% or less on the to-hit roll and needs to generate Righteous Fury, and the Crew still get to make Arduous (-40) Tests to resist being Stunned/Fatigued. Even then, the truck is probably blasted to atoms and the crew/passengers will be lucky to be alive, let alone Stunned or Fatigued…

Alekzanter said:

I might also add…The to-hit roll also needs to be a successful Test.

There are a few places that Only War breaks down and one of them is vehicle combat. The rules do not have enough granularity to them, but, as one of the writers told me during the beta when I pointed these problems out and listed some solutions "This is not a tank sim".

A weapon that fires a high explosive charge against a vehicle is actually more likely to injure the crew than stun them, due to spalling. We've been treating Concussive by, instead of stunning the crew, it causes 1d10-5 x rating damage at it's rating str and ap 0 to the crew inside the tank if it fails to pen. (thier armor and toughness bonus apply)

This can be further reduced by a spall liner.

BaronIveagh said:

"This is not a tank sim." Nice. Balanced rules that make sense within their own mechanical context…seems a reasonable expectation. I'm very interested in seeing your short list of noted problems and solutions.

You have an interesting alternative to Stunned/Fatigued. Would you mind walking through an example?

Regarding spall liner: Would this then be something that is non-standard on Imperial AFVs/APCs? Your statement leads me to believe this would be the case. Are some vehicles, such as the Sentinel Walker, excluded from having this installed due to space/surface issues? Would spall lining be something the crew have to requisition independently through the use of Logistics? What might its Availability be? Would there be any need for differentiating between hard liners and blankets, or might it just be "generic" spall liner? Assuming you have worked spall liner into your game, how does it mitigate the Damage outlined in your House Rule?

I keep coming back to this topic thinking I'm missing something obvious, and here you have this elegant proposal that makes mine look like an Ork Buggy by comparison. You know? It works because I think it works.

A 1 round stun is equivalent to 6 seconds of being dazed, no?

Looking at hull critical damage for comparison…

The toughness test for stun for a vehicle destroyed(Critical 9) is -10.

+10 for a critical 3, that being a jostling of the vehicle around- IF you aren't wearing your seatbelt or otherwise secured, in which case no stun. I would probably take the latter if anything, with respect to concussion. Just wouldn't want a weapon quality to outstrip the critical damage charts in effect per shot.

If the shot has bypassed structural integrity and penetrated the crew compartment, however, all bets are off. Or if the vehicle was open topped.

I would not question the realism at all. For example nearly all the tank crew casualties from IEDs in Iraq and Afghanistan have come from high explosives and traumatic brain injuries that result. A large enough explosion near any armored vehicle will still result in shock waves inside the crew compartments and very possibly serious injury.