Answer: very poorly. It's on the Defense Modifiers table:

Getting knocked on your ass makes it harder to dodge subsequent attacks. It's in the rules and everything.

-Frank

SR knockdown isnt the 2 meter flying sillyness of hollywood fame. basicly you colapse where you stand. this can fully happen based on stuff like getting knocked of balance from a hit in the leg and similar.

Consider this, you're firing gel rounds out of a gun with a high damage rating, like 5 or 6. Gel rounds ad +2 to the DV of the gun putting it now at 7 or 8. 'Course, the person gets +2 AP as well, so they will have more dice to resist the damage.

Now, if the target has 10 stun boxes and 10 physical boxes and has taken, let's say 8 boxes on each, there's only 2 stun wounds and 2 physical wounds that this target can take before death.

So, if our gel round gun is firing at 7 DV and we have 9 dice to roll for three hits on average and we increase that DV to 10. Assume, for the sake of arguement, that after all the negative modifiers to dodge pool due to to damage, the target doesn't cancel any of those hits. The damage resistance goes well, and the target gets 4 hits. However, that still leaves 6 damage to be applied. Therefore, the stun condition monitor is filled, leaving 4 damage to be applied to the physical condition monitor. 2 more on that one put the target all but in the kill column.

If I were the mage in question, I'd just stay down and cast from there.

True, if you don't mind the -2 modifier to dodge tests...

A lot of melee adepts? .

Certainly acceptable in some situations, yeah, but understandably undesirable in others.

Say, don't ranged attacks also suffer -2 dice when the target is prone, or some such? And melee gets +2?

I might be making that up, since I don't recall where I saw that.

Not personally, no, but then I don't know a lot of people who are likely to get into a gunfight.

There are plenty of examples of people doing all sorts of weird shit after getting shot, and charging the person who shot them is one of the less insane (and more common) actions. If the target is charging you before you shoot him, it's quite likely that's what he'll be doing after you hit him, unless you put him down for good.

Actually, knockdown depends on the damage you take - after resisting it.

The one person that I personally know that was shot by a firearm was hit while running away from the shooter, in the dark. He knew he was getting shot at, and shot at a lot, which is why he was running like hell for cover. He fell down when hit. He got back up and when he joined the others he was with, and who had seen him get hit, they started checking for the hole. He was puzzled as to what they were doing. He didn't know he had been hit, the ceramic armor had protected him although it ruined the armor.

He thought he had tripped even though it had knocked him over. So it wasn't a concious psychological thing. Although he was somewhat offbalance because he was running, it was the actual physics of the force of a rifle slug at 300m, with energy dispersed by body armor, that "knocked" him down. Better to say tipped him over.

There are likely more accurate ways of modeling it, but I'm more or less OK with the general idea of knockdown in the game.


EDIT

Having some sort of Agility, or Reaction Test factoring in what you are currently doing seems to strike me as the way to go. If you don't mind the extra work involved that is.

If you received Deadly Damage, you were always knocked down.

I got into a forum debate a while back on the same thing. My opposition suggested that handguns really couldn't provide the necessary force to lay someone out. My position is that falling over is more of a function of unexpected torque than brute force.

unless the damage comes from a nice load of explosives. at that point you isnt as much knocked down as spread all over the pavement...

I'll agree to that. And everyone who says different, must provide the evidence, in my eyes.

Right. Body in Shadowrun basically represents both your mass (size) and your physical integrity (health).

Greater mass would make you more resistant to getting knocked over, while greater physical integrity would make you more resistant to staggering due to sudden trauma.

So attributing knockback resistance to the Body attribute covers both bases in a nicely pat manner.

The actual shove generated by the impact may well have been a factor, even the main factor since he was already out of balance (sprinting is just a continuous falling forward), but I wouldn't discount the possibility of the sharp impact fucking with his nervous system and muscles. For example, the momentum possessed by an average 7.62x39mm FMJ fired from an AK-47 at a range of 300 meters is equal to a 5oz baseball at 87.2fps, or a 12oz coke can at 36.3fps.

You're more familiar with what happened of course, I'm just mentioning the possibility because there have been plenty of instances where a person has had a fully penetrating injury from a firearm that causes an insignificant momentum transfer without realizing they were shot, and still fall down. Likewise plenty of people have taken non-penetrating hits from rifles without expecting it or realizing it until it has been pointed out to them, without staggering at all.

AFAICT, if someone falls down as a result of a gunshot wound, it's a physiological or psychological reaction (such as Zen_Shooter01 described earlier in the thread) in the massive majority of cases. Hence I don't really agree with linking such a test with Agility -- Willpower and Body seem likelier.

That opposition was me. To quote myself from that thread, "For example, a 230gr (14.9g) .45 ACP bullet traveling at 950fps (289.6m/s) has 4.3kg*m/s of momentum. Assuming the bullet stops within the target, the amount of momentum transferred is equal to being hit by a baseball (5 ounces, 141.7g) moving at 99.9fps (30.5m/s), or someone tossing a 2lb (0.907kg) bag of candy to you at 15.6fps (4.8m/s). Do batters who get hit by pitchers in a major league game tend to fall on their asses from the impact? If you toss a 2-pound bag of candy to someone [who's not expecting it], do you expect to get knocked down?"

It's not about energy, but momentum.

I'm not criticizing the validity of the math at all.

Other than the physiological and psychological effects? No difference that I can see.

It's gotta be magic, then. Millions of little microscopic fairies with little microscopic banana peels, maybe.

Not really. I wasn't there. I've pretty much related the extent of my knowledge of it to you. The only other question I asked was if he ever found out what firearm it was that he was shot with. Which he didn't as they were not armed at the time for offensive combat, so going in the opposite direction of the person that just shot him seemed like the right idea. After that I just let it rest.

Catching a 50 mph fastball? That moves your arm noticably even when you are expecting it. Leveraged correctly on a person that is unaware or not expecting and is in a percarious balance situation might tip them over. Even if just throwing off footwork enough to cause a trip.

Yes, I suppose it is possible that falling was caused by an overloaded nervious system that turned his legs to jelly momentarily, and he didn't notice it happen because he was already running on adrenaline. The first person's perspective of events can be misleading when taken verbatum. People that have a stroke and fall as a result will often not realize they had the stroke before they fell, and thus not realize that the stroke was not the result of the falling injury.

Exactly. Like I tried to explain in the last thread, kinetic energy really has nothing to do with it. You can get air guns that generate much more kinetic energy at the muzzle than a 2lb bag of candy at 15.6fps.

I'm still lost. If you agree that the injury (which is completely separate from issues of kinetic energy, momentum, torque, etc.) isn't the cause of the knockdown and that the consequential physical variables are more or less equal between a bag of candy and the bullet, then it certainly seems like you're claiming there's some kind of bullet magic that makes people fall down.

True. But the same amount of work on a bottle of milk can hold it in place for 1 hour or launch it into space by applying that work over a shorter period of time. Gravity, and for that matter musculature apply constant forces, so if you want to "overcome" them applying your prospective work over a shorter period is what you want to do.

-Frank

Since I cannot think of any way to calculate the force that any of the projectiles mentioned causes on a human, I cannot really argue with this. I have a feeling that'd be most important if the target object had a very precarious point of balance, and a fast push over a very short distance were enough to cause it to eventually fall down. For simply pushing someone over, it seems to me this wouldn't make a difference, and in any case all the example impacts will be over in a fraction of a second.

I can agree with that. It might, in the right place at the right time. But I would say that considering all the things that might happen in combat, that's not something I'd want rules for. The body's reaction to the injury itself is a far more common culprit, so that's the obvious thing to base the rule on.

Didn't think of that. (I pretty much flunked physics in high school and haven't studied it since.) Makes a lot of sense, actually.

Right now in SR4 Body is already reducing the chance of knockdown twice because it is damage after the soak that is then compared to the Body.

What I was thinking of was using this as the base. But instead of a certain knockdown if this occurs, instead an Agility Test after that to try recover afterward. Threshold is the number of boxes your Body was exceeded by, or Damage-10 if your Body is over 10. Die modifiers for things like running, kneeling, climbing or hanging from a rope, etc.

Not sure that fits the example I gave. I don't really know if Stun damage exceeding Body was particularly applicable. I found it kind of socially awkward to ask a lot of questions.

"Yeah, I've been shot."

"Oh, really. Did you die?......How 'bout that local sports team?!"

Let me put it this way:

When I stick my foot out to trip someone, they fall over without me having to break their ankle to do it. Certainly, if I bust a bone or twist a tendon in the process, they're more likely to eat dirt, but it isn't necessary for my desired result.

All I've done is create unexpected torque -- and my foot doesn't even need to be powerful enough to actually do the work of knocking them over by itself, as the subject can overcompensate on his own and go flailing. Add a simultaneous flinch in there and sure, the guy's going to have problems with verticality.

I wholeheartedly agree that you're not going to see knockback from small arms fire (unless there's the previously-mentioned flailing). I'm pleased that SR4 removed that element, despite what my uberstrength trolls might prefer. Wasn't there a MythBusters episode that dealt with knockback from handguns, not too long ago? IIRC the findings were that it'd take a shotgun to actually get some knockback. All the pistol fire did was some violent nudging.

Regardless, there is a term associated with firearms called "knockdown" or "stopping power." It's used to discuss the capacity of a slug to put a target on his rear (literally or figuratively). Rounds that overpenetrate are less likely to do this, while rounds that fragment or flatten (or otherwise transfer as much kick to the target as possible) are more likely to demonstrate "knockdown."

In SR4, this is represented by the relationship between the target's Body and the damage dealt. Ergo, we have our abstracted representation of getting shot. It's not a superaccurate representation of the laws of physics, but it's good enough for a roleplaying game.

Thinking about it a bit more Agility is already the most heavily weighted Attribute, so if we are talking about a toss-up then from a game perspective it might not be the best choice. I could see Willpower to regain your motor control being ok too, because we are talking about a temporary stunning effect.

Having it a Willpower+Agility Test I think would lead to knockdown without a knockout being so rare that you might as well just remove the rule....which may or may not ultimately be the closest model of reality.

What about Reaction? It represents your reflexes.

Make it Reaction + Gymnastics, mayhap.