Expanded Guns Tables

[KingSkin]

That sound like exactly the sort of thing I'm looking for. I like it when individual firefights can risk killing people, it encourages tactical play and more realistic reactions to danger. But I also hate the amount of downtime that can be taken if a character gets badly injured. I know it's more sensible and I don't like the D&D healing potion style for the games I want to run. But realistic healing rates can make it a bitch if the players are up against a time limit but 3 of them can't get out of bed for a couple of months.

I had a look at Edge of The Sword yesterday. His 'Sword' system is one of the most convoluted things I've ever seen. To work out damage you have to do something like six stages of multiplication - taking into account things like muzzle velocity, round type (hollow points, lead slugs, glaser rounds, etc), diameter of round, thickness of limb hit. And loads more - Then you apply that number (about an hour after you started I reckon) to the targets body. There are something like 28 separate hit locations if you include both hands, etc. And it looks like anything more powerful than a rubber band hitting you in the head will kill you outright no matter how many hit points you have.

[rleduc]

I had a look at Edge of The Sword yesterday. His 'Sword' system is one of the most convoluted things I've ever seen. To work out damage you have to do something like six stages of multiplication - taking into account things like muzzle velocity, round type (hollow points, lead slugs, glaser rounds, etc), diameter of round, thickness of limb hit. And loads more - Then you apply that number (about an hour after you started I reckon) to the targets body. There are something like 28 separate hit locations if you include both hands, etc. And it looks like anything more powerful than a rubber band hitting you in the head will kill you outright no matter how many hit points you have.

I love complex game mechanics -- but I know that love is not universally held -- so what I was trying to do with the Risk/Fire Arms system is to create an alternative to "ablative hit points" that creates dramatic tension, doesn't break the "suspension of disbelief" of people with some familiarity with fire arms, and is fast and fun to play.

To me the original RuneQuest (1) rules were designed to simulate SCA fighting -- there was a huge overlap in those two communities in the late 1970's (myself included). What I wanted with the fire arms system is something like the original RQ combat (that is, fast and easy to play, and gives a "first order" approximation of reality) but not centered on SCA-style melee combat, but rather small fire fights.

Someone on RPG.net once complained about my system reduces risk for darkness -- but I would argue this makes perfect sense in light of the above. If you think about the "accepted" two step process for modeling injury in RPGs you first determine if your attack caused any injury (the roll to hit and possibly defensive rolls) and then a roll for damage. This is just a model! It is not set in stone. Morrow Project realized that most modern fire arms deliver a very consistent amount of force, so in that system a fire arm did a fixed amount of damage, and the hit location roll was a surrogate for the damage roll. In my system, you use standard BRP rules for determining if there is a hit, and then the "risk" is a (hopefully easy to compute) intermediate before the damage roll -- the risk gets modified up or down depending on the conditions of the firefight (for example skilled shooters get a small increase, and novices a small decrease) -- and then a damage roll is made.

[Nightshade]

One problem with that is that even hit location isn't the complete answer here; people are notoriously idiosyncratic in how they respond to gunfire. One study I read said that, in essence, there were four possible results (during the course of an actual combat; afterwards all kinds of other things set in, but they were very rarely a factor during the actual fight) of getting shot: shocked out (which could mean either physical shock or psychological reaction), bleeding out, nothing noticeable, or the (actually surprisingly rare) traumatic organ disablement.

Everything else, including meaningful disablement, didn't actually come up during the course of a firefight; even things we'd think would impair tended to get lost in the up and downsides of adrenaline surges (i.e. the adrenaline helped you in some ways and hurt you in others, but between the two it tended to to make even things like tendon damage largely unnoticeable until you'd had time to come down off it).

Presumably this applies to melee combat to a large extent too, but the study didn't look into that, being based primarily on law enforcement shots fired afteraction reports.

Edit: Sort of lost my point, which was you couldn't predict which one you'd get from, well, much of anything. There was a general tendency toward the stronger effects with higher caliber weapons, but even there it wasn't consistent, and even headwounds (where hydrostatic shock is an actual issue, unlike the rest of the body) weren't particularly consistent.

[KingSkin]

@ Rdeluc: That sounds like a good way to go. I downloaded the rules but haven't had a chance to read them yet.

I don't mind complex systems but don't like it when they get in the way to little appreciable effect. Unfortunately I think the Sword system fails that test.

In my own (non-BRP) system I use D100 skill rolls and the 10's dice gives the quality of the attack. All weapons have damage multipliers that are applied to the Quality to determine damage. That way you can include both how good the shooter is (better shooters can hit with higher quality attacks) and also how powerful the weapon is. It also uses an Action Point system like the X-Com games which I like because it makes tactical choices a lot more important.

Anyway, point is that I tried to keep it relatively simple because you can get too caught up in the details of combat (especially guns) and it rarely adds that much to it.

While I do like a healthy dose of abstracted realism I also love Feng Shui's approach because it suits the source material.

I think your system sounds like it strikes the right balance though and I bet if you get a bit clever-clever you could use the Risk to model a lot of different variables. I'm wondering now if I can tie it into my Fear system...

@Nightshade: I know what you mean, everyone you speak to has a different answer and a lot of the evidence contradicts itself. Problem is that there are so many variables and it's so generally such a traumatic event for the body that it's hard to correlate cause and effect. For instance: My mate Kenny the Commando once told me what happens when you fire a heavy machinegun into someone and from what he said the phrase 'total limb disablement' would seem to fit. I remember reading somewhere that with an HMG it's the air cones that come with the rounds that do the real damage. And I've heard so many different things about hydrostatic shock that I tend to ignore more things concerning that these days.

[Bleddyn]

One problem with that is that even hit location isn't the complete answer here; people are notoriously idiosyncratic in how they respond to gunfire. One study I read said that, in essence, there were four possible results (during the course of an actual combat; afterwards all kinds of other things set in, but they were very rarely a factor during the actual fight) of getting shot: shocked out (which could mean either physical shock or psychological reaction), bleeding out, nothing noticeable, or the (actually surprisingly rare) traumatic organ disablement.

Everything else, including meaningful disablement, didn't actually come up during the course of a firefight; even things we'd think would impair tended to get lost in the up and downsides of adrenaline surges (i.e. the adrenaline helped you in some ways and hurt you in others, but between the two it tended to to make even things like tendon damage largely unnoticeable until you'd had time to come down off it).

Presumably this applies to melee combat to a large extent too, but the study didn't look into that, being based primarily on law enforcement shots fired afteraction reports.

Edit: Sort of lost my point, which was you couldn't predict which one you'd get from, well, much of anything. There was a general tendency toward the stronger effects with higher caliber weapons, but even there it wasn't consistent, and even headwounds (where hydrostatic shock is an actual issue, unlike the rest of the body) weren't particularly consistent.

If anyone is interested in discussing this that I suggest they read up on the Tactical Combat Casualty Care and the PHTLS (adavanced-Militaray)/ATLS course materials. Wound Cavitation from high velocity rounds and care from the platinum 10 minutes through golden hour to the silver 24 gives you a breakdown in the lethality of GSW's per location.

[Bleddyn]

@Nightshade: I know what you mean, everyone you speak to has a different answer and a lot of the evidence contradicts itself. Problem is that there are so many variables and it's so generally such a traumatic event for the body that it's hard to correlate cause and effect. For instance: My mate Kenny the Commando once told me what happens when you fire a heavy machinegun into someone and from what he said the phrase 'total limb disablement' would seem to fit. I remember reading somewhere that with an HMG it's the air cones that come with the rounds that do the real damage. And I've heard so many different things about hydrostatic shock that I tend to ignore more things concerning that these days.

.50 cal rounds will tear your flesh open with in a certain amount of distance and they do tear limbs off.

[Atgxtg]

Most of what I7ve seen agress with Niteshade's post. In a nutshell, unless someone gets hit with a massive amount of damage, then chances are they won't die outright, and how they deal with the injury is as much a matter of their personality and psychology as anything else. Yeah, the bullet might kill the guy, eventually, but he might do a lot of damage before then.

[Atgxtg]

.50 cal rounds will tear your flesh open with in a certain amount of distance and they do tear limbs off.

I can see them tearing flesh open, but I would think that tearing limbs off would be unlikely. I would expect them to just punch right though something like a body.

Maybe if it hit a major bone at just the right angle, that might @rpvode enough resistance.

[Bleddyn]

I can see them tearing flesh open, but I would think that tearing limbs off would be unlikely. I would expect them to just punch right though something like a body.

Maybe if it hit a major bone at just the right angle, that might @rpvode enough resistance.

They will on contact.... 50cal rounds will tear limbs off, ask any vet. I still have my headspace and timing key.

[Atgxtg]

They will on contact.... 50cal rounds will tear limbs off, ask any vet. I still have my headspace and timing key.

That is very interesting. As I posted eariler, I ould have expect the .50 cal to just punch right rough, and not dump enough energy to rip off limbs. Maybe this is a case of the human body's elasticity working against itself.

If you had made this claim with a hand held firearm, I wouldn't have believed you, but a .50 cal is another story.

[Nightshade]

And to be clear, I was referring to small arms in my post; .50 calibers and up are starting to get into a whole different ball of wax (though even there from what I've seen from WW2 references, the results aren't completely consistent; one of my uncles had a WW2 era scar where he'd gotten a friendly fire hit, and apparently kept going (though it was a hell of a scar and if it'd been more dead on I can see how that could have been a disabler). But apparently that doesn't apply to anything much smaller (since the study I saw even included some 7.62 and 5.56 data)>

[Atgxtg]

And to be clear, I was referring to small arms in my post; .50 calibers and up are starting to get into a whole different ball of wax (though even there from what I've seen from WW2 references, the results aren't completely consistent; one of my uncles had a WW2 era scar where he'd gotten a friendly fire hit, and apparently kept going (though it was a hell of a scar and if it'd been more dead on I can see how that could have been a disabler). But apparently that doesn't apply to anything much smaller (since the study I saw even included some 7.62 and 5.56 data)>

Ballistics are like retail. Location, location, location. With small arms, there are actually very few spots on the body that one can shoot that will instantly incapacitate or kill an opponent. It is easy to inflict a potentially lethal injury, but that might not stop the guy from fighting on.

[Nightshade]

Ballistics are like retail. Location, location, location. With small arms, there are actually very few spots on the body that one can shoot that will instantly incapacitate or kill an opponent. It is easy to inflict a potentially lethal injury, but that might not stop the guy from fighting on.

Yeah, this. The surprise was that it apparently doesn't even seem to impair them much, most of the time. That was pretty counterintuitive.

[Atgxtg]

Yeah, this. The surprise was that it apparently doesn't even seem to impair them much, most of the time. That was pretty counterintuitive.

Yup. That is becuase years of fiction and gaming got us trained to think otherwise.

A good way to look at it is the way animals react. People are often suprised at how dogs, bears, deer, and other animals keep going when they have been wounded, and attrubte to some special "toughness" that animals have. It isn't that the animals are any tougher than people, they just haven"t been taught that they are supposed to lie down and die when they get hit.

In real combat the "adrenaine dump" will compensate for the pain. In fact, if they didn"t notice they got hit, they might not even be aware that they are wounded. I think most of us have been in a tense situation/fight where they got hurt and didn't notice it until after the crisis was over. It is why people who have accidents often say that they are alright and then find out that they aren"t later. It really isn't that counterintuitive, at least not compared to real world expereinces. It is only counterintutive to use becuase years of fiction and gaming have convinced us to think otherwise.

About the only games that come close to working this way are Timelords, CORPS, and to a lesser extent, Bond.

[Smoking Frog]

And to be clear, I was referring to small arms in my post; .50 calibers and up are starting to get into a whole different ball of wax (though even there from what I've seen from WW2 references, the results aren't completely consistent; one of my uncles had a WW2 era scar where he'd gotten a friendly fire hit, and apparently kept going (though it was a hell of a scar and if it'd been more dead on I can see how that could have been a disabler). But apparently that doesn't apply to anything much smaller (since the study I saw even included some 7.62 and 5.56 data)>

I think you have to be careful about painting with too broad of a brush. Depending on the length of the barrel on the weapon firing the round, and the range to the target, the velocity of the round at impact can vary greatly. (And velocity determines the energy at impact.) I think it is better to try to assign damage values based on the combination of bullet plus weapon (and range to be more accurate, so a rifle should do more damage than a carbine firing the same round at all ranges, and at farther ranges, every round does less damage. Also, there seems to be a lot of variability in how a particular round performs. If a 5.56 round is going 2,700 f/s on impact, the expectation is that it will fragment and tumble in the body, increasing the damage done considerably. But recent combat experience seems to indicate you can't count on fragmentation or tumbling. (If you get it, the victim is probably toast.)

Also, because of impulse, the damage done by an automatic weapon getting more than one hit essentially simultaneously is much higher than the same number of hits spread over time. Someone who was a machine gunner in the Vietnam War described seeing people "come apart like rag dolls" when they were hit with multiple 7.62 rounds.

And there is one other aspect to being wounded that can incapacitate you: intense pain. Someone who was wounded in Vietnam by a 7.62 (Warsaw Pact) round described the pain as so intense that it was totally incapacitating and was not controlled by the first two injections of morphine he got. The third injection knocked out the pain but also put him in Lalaland. This was a leg wound that did not do any permanent damage in that he was able to fully recover.

I think if you want to simulate what happens when people get hit with military grade ammunition at rifle velocities, you have to account for both the possibility that you might get lucky and the round does not hit a bone, destroy a vital organ, etc. (so you might still function), and also the possibility that a single round could effectively amputate a limb if it hits the bone or completely destroy vital organs by fragmenting or tumbling inside the person. You should probably also take into account that at longer ranges, the velocity is lower and the damage less.

Critical hits and specials might be the simplest way of dealing with the variability of this.

[KingSkin]

Yeah, I think crits and specials are the best way of dealing with the upper lethality range of hits, that's exactly what they're there for.

Something I was reminded of when you mentioned multiple simultaneous hits it that most types of modern body armour can't do a damn thing about them. The kinetic force is just too much for them to spread over the armour all at once so they'll tear straight through. I think the best way to model that would be to use the idea of Threat levels from Rich's Modern Firearms Guide (which I've now read and really like) and assume that multiple strikes automatically reduce the armour's value to 'below the Threat' so they're much less effective.

In fact, if you check the warranty on a bullet-proof vest some of them only cover manufacturing defects and not damage and even those that do specifically mention getting shot point out that the warranty is voided after taking a single hit.

That's also something that could be worth taking into account if you want to get hyper-detailed although it would probably jar with most people as we're used to armour reducing damage directly which isn't how it really works.

[Nightshade]

I think you have to be careful about painting with too broad of a brush. Depending on the length of the barrel on the weapon firing the round, and the range to the target, the velocity of the round at impact can vary greatly. (And velocity determines the energy at impact.) I think it is better to try to assign damage values based on the combination of bullet plus weapon (and range to be more accurate, so a rifle should do more damage than a carbine firing the same round at all ranges, and at farther ranges, every round does less damage. Also, there seems to be a lot of variability in how a particular round performs. If a 5.56 round is going 2,700 f/s on impact, the expectation is that it will fragment and tumble in the body, increasing the damage done considerably. But recent combat experience seems to indicate you can't count on fragmentation or tumbling. (If you get it, the victim is probably toast.)

Its possible, but as I said, the data I had included some 5.56 and 7.62 data, including some from fully automatic weapons, and it didn't seem to change anything (of course this was presumably assault rifles, where with the typical users in the typical situations tightly spaced hits are very unlikely; it may indeed be a different beast with light machine guns).

And there is one other aspect to being wounded that can incapacitate you: intense pain. Someone who was wounded in Vietnam by a 7.62 (Warsaw Pact)

That was lumped into the shock and psychological result in the report. As with other such elements, it was extremely inconsistent.

round described the pain as so intense that it was totally incapacitating and was not controlled by the first two injections of morphine he got. The third injection knocked out the pain but also put him in Lalaland. This was a leg wound that did not do any permanent damage in that he was able to fully recover.

Well, that's the other half of that; it was inconsistent both ways. You'd get some people who would suck up 4-5 high caliber rounds with no apparent impairment at the time, and some would take one small caliber round and immediately fold up.

I think if you want to simulate what happens when people get hit with military grade ammunition at rifle velocities, you have to account for both the possibility that you might get lucky and the round does not hit a bone, destroy a vital organ, etc. (so you might still function), and also the possibility that a single round could effectively amputate a limb if it hits the bone or completely destroy vital organs by fragmenting or tumbling inside the person. You should probably also take into account that at longer ranges, the velocity is lower and the damage less.

Single shots from assault rifle rounds are extremely unlikely to severe a limb (I make the qualification because you have a point with tightly spaced autofire bursts, but that's unlikely to come up when fired from an assault rifle, as compared to the situation with light and medium machine guns).

[Atgxtg]

Yeah, I think crits and specials are the best way of dealing with the upper lethality range of hits, that's exactly what they're there for.

Nah. They were there to help simulate ancient combat where you could occasionally slip a blde in through a gap in the armor. I also think crtic are not a great way of handling firearm leathity, either. At least not with the way body armor works in BRP. Too many underpowered rounds will "impale" though body armor that it couldn't penetrate.

Something I was reminded of when you mentioned multiple simultaneous hits it that most types of modern body armour can't do a damn thing about them. The kinetic force is just too much for them to spread over the armour all at once so they'll tear straight through.

Do you got any data on this? I was under the impression that the rounds wouldn"t penetrate. Can a burst from an Uzi really "tear though" a NIJ III vest?

[filbanto]

Hey guys - this thread is great, but what I really need is some hard evidence that a SIZ 4 intelligent rat will be able to shrug off small arms fire with impunity. In 6 hours Rich is subjecting our Rubble & Ruin party to a "Mad Max" style car chase. There's 20-30 First Church of the Apocolypse zealots on bikes and trucks and my character's drive skill is only 46%

[rleduc]

Dummm, deee dumm dum...

T minus 3 hours.

[KingSkin]

Nah. They were there to help simulate ancient combat where you could occasionally slip a blde in through a gap in the armor. I also think crtic are not a great way of handling firearm leathity, either. At least not with the way body armor works in BRP. Too many underpowered rounds will "impale" though body armor that it couldn't penetrate.

In which case the bullet has also avoided the body armour, just like the knife did in your example. As far as I can see the damage ranges for each weapon coupled with specials and crits are more than enough to take into account how well a given round hits you and how much of an effect it has. The both mental stress and physical trauma are accounted for by the hitpoints. Maybe it was a .22 and you rolled a special. Looking at real world statistics it's easy to say, no way could that do 12 points of damage, that's enough to kill a health man. But when it happens in the field maybe it just hurts like **** and there's claret everywhere and you've decided you really don't like getting shot so if it happens again you're going to sit this one out. That's how I'd explain any problems on that side of it.

Do you got any data on this? I was under the impression that the rounds wouldn"t penetrate. Can a burst from an Uzi really "tear though" a NIJ III vest?

Not that I can point you too. It was a few years ago I read it. Perhaps I chose my words a little hastily as well. I don't mean they'd literally tear the jacket apart but it won't be able to absorb enough of the kinetic energy to save you. They may not actually penetrate but that energy has to go somewhere and Kevlar plates have a limit to how much they can handle.

[Smoking Frog]

Do you got any data on this? I was under the impression that the rounds wouldn"t penetrate. Can a burst from an Uzi really "tear though" a NIJ III vest?

Uzis fire pistol ammunition, although depending on the version they have longer barrels than most pistols, so the round is coming out with greater velocity. I've not seen anything about how vests fare against that type of round. As I recall, the Marrow Project had a damage calculation that took muzzle velocity into effect, so a 9mm round from a pistol would do less damage than from an Uzi. (Now that is a flash-back to my ill-spent youth!)

As far as rifle ammunition goes, I can just cite the experience of the US combat troops in Iraq and Afghanistan. Their Kevlar vests are not proof against rounds from rifles or machine guns. The troops are issued ceramic plates to give them rifle-stopping protection.

My earlier reference to a round "effectively amputating" a limb if it hits the bone was not meant to suggest you're going to get many limbs sheared off. But if you have a bone shattered and significant damage to the muscles, the limb may be just hanging there "flapping in the wind." Whether it's still attached or on the ground, you're not going to be using that arm or leg for anything. And you may be quickly bleeding to death.

There's a difference between surviving a hit and ignoring it. I was told that the FBI started to emphasize agents' practicing shooting with their "off" hand after a gun fight in which an agent was shot by a pistol. If I remember the details right, the agent was hit in his right arm, and he couldn't use it. He had to cock his shotgun with his left hand and then aimed and fired off hand, which actually worked since he killed the other guy. Also along those lines, if you read "Black Hawk Down," you may remember the comment of a SAW gunner who had been issued state of the art Teflon coated bullets, which were supposed to be super dooper good against people in body armor. More than once he hit a Somali -- none of whom had body armor, of coure -- with multiple rounds which just passed through. Guys would be knocked down, then get up and run way. I would doubt seriously, though, that a guy with multiple "pass through" bullet wounds would be anything like 100% fit, even if he was able to get up and get away.

Apropos of the chance of being overcome by intense pain, I recently read some first-hand accounts of the Battle of Attu Island during WWII. One particularly intrigued me. The US ground troops had not been in combat before. One platoon leader after the battle commented that he was glad that they had been briefed about some of the realities of combat, particularly how wounded men screamed. He wrote that it was unnerving and he was glad he had been at least warned about it. That obviously doesn't mean everyone is screaming after getting shot, but it happens enough that it was addressed before the battle.

The main point I would make is that if you want to simulate the effects of real military-type weapons, you have to have a system in which people neither always survive rifle hits nor always die. There's a huge range of possibilities (from instant death to "merely" having a hole in you") and a "realistic" simulation would need to take that into account.

[dragonewt]

Blacksburg Tactical Research Center: Guns! Guns! Guns!

[Nightshade]

The main point I would make is that if you want to simulate the effects of real military-type weapons, you have to have a system in which people neither always survive rifle hits nor always die. There's a huge range of possibilities (from instant death to "merely" having a hole in you") and a "realistic" simulation would need to take that into account.

Can't argue with any of this, but I do have to repeat that at least according to the information in that study, actual limb impairing hits are extremely uncommon; even ones you'd think that would didn't seem to have an immediate effect. That said, this included a range of weapons including handguns, shotguns and some rifles; a situation where the mix is one of primarily rifles through medium machineguns could have provided a different result.

(And again I have to emphasize this is not discussing longer term effects; the same people who walked out of the fight bleeding but operant might well fall over dead fifteen minutes later and/or be unable to do much effective two hours later.)

[Smoking Frog]

Can't argue with any of this, but I do have to repeat that at least according to the information in that study, actual limb impairing hits are extremely uncommon; even ones you'd think that would didn't seem to have an immediate effect. That said, this included a range of weapons including handguns, shotguns and some rifles; a situation where the mix is one of primarily rifles through medium machineguns could have provided a different result.

I've been focusing on military type rifles. If you mix pistol, shotgun, and rifle data, I think it's like looking at traffic fatalities and not distinguishing when cars are going 65 mph and when they are going 25 mph. The formula for kinetic energy is E = 1/2 (m*v[squared]). So velocity's relation to the energy is exponential. Just to give an example of the relative difference you'd be dealing with, here's some examples from the Wikipedia article on Muzzle Energy. The specific energies are of course approximations, but the hopefully eye-opening point is the enormous difference between energy levels once you get into rifle ammo, which produce much higher velocities. Here's some items for comparison:

Round Engergy in Joules

9mm 519

.45 ACP 564

5.56 x 45mm 1,796

7.62 x 51mm 3,799

.50 BMG 15,037

The energy level of the 5.56 round was something like 3.5 times what the pistol rounds produced. And obviously the .50 is out of the world, but even the 7.62 has more than 7 times the muzzle energy of the 9mm. If you look at actual rounds from actual weapons, obviously you'll get a lot of variety, but this shows you the scale of comparison. Just to compare, if we assume that HP of damage done is 1% of the muzzle energy, the HP you'd lose from each of these would be:

9mm 5 HP

.45 ACP 6 HP

5.56 18 HP

7.62 38 HP

.50 150 HP

Obviously one could argue all day about what the appropriate measure of damage should be, but kinetic energy is obviously a big part of that equation. Given how disparate the energy levels are, to be realistic, I think you need to keep pistol data and rifle data separate. There's loads of data on pistol shootings because that is what law enforcement shoot outs usually involve.

Your chances of having your arm remain functioning after getting shot obviously change when the energy you absorb goes from 519 joules to 3,799. And think about something with that much energy hitting you in the chest, not to mention the head!