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Crusher Bob
Since I don't think it's come up on the new boards, and I didn't want to get involved on the firearms thread, here's some stuff about armor, hit locations and other interesting bits:

First question? If we wanted to make a random hit table, what percentages should we use for each location of the body?

Surveillance for Fatal and Nonfatal Firearm-Related Injuries --- United States, 1993--1998
Gives the following approximate hit location percentages for non fatal shootings (assault/intervention type) in the US as:

arm 0.13
leg 0.33
head 0.14
torso 0.21
abdomen 0.16
undetermined 0.03

Our next step is to distribute the undetermined 3% into the other areas, so we don't have to deal with it later. This gives:

arm 0.134
leg 0.34
head 0.144
torso 0.217
abdomen 0.165

But this data only accounts for non-fatal shootings, how do we account for the fatal ones?

An Analysis of Wound Statistics in Relation to Personal Ballistic Protection (pdf file)

Tells us that, during the Vietnam war, hits with small arms fire in the following areas had the following chance to be fatal:

arm 0.01 (rounded up to 1%)
leg 0.05
head 0.7
torso 0.51
abdomen 0.4

assuming 1000 non-fatal shootings, we then go on to use the above numbers to determine the number of fatal shootings that would have hit the same location

           Non-Fatal       Fatal    Total     % hit
arm          134          1       135       0.08
leg          340        18       358     0.212
head         144       336       480     0.283
torso        217       226      443     0.262
abdomen       165       110      275     0.163
totals       1000      691     1691

This gives a lethality rate of small arms fire of around 41%, which greatly overstates the case of small arms lethality (closer to 33% or even 25%). So I thought this data might be useless. But it more of less agrees with Table 8 in the same paper, so I'll go with it.

The head gets shot a lot. That's why smart live soldiers keep their helmet on

For those of you insisting on a random hit location table, i give you one using 2d6:

2 head
3 head
4 head
5 head
6 torso
7 abdomen
8 torso
9 leg
10 leg
11 arm
12 arm

Which produces the following hit percentages (with comparison to the above data):


       Random     Data
head       0.278   0.283
torso      0.278   0.262
abdomen   0.167   0.163
leg        0.194   0.212
arm        0.083    0.08

So it's pretty close


Now, what about armor?

I'll be basing my numbers on the NIJ standards, so here they are:
Ballistic Resistance of Personal Body Armor NIJ Standard–0101.04 (pdf file)

Thus I somewhat arbitrarily give the following number of armor dice for the following classes or armor (along with a guess about what the armor will be like in 2070 (rigid, cloth, etc)

I 9 cloth
IIA 12 cloth
II 15 flexible
IIIA 18 flexible
III 21 semi-rigid
IV 24 rigid

So how does this compare with the game values of SR4s armor?
Using some math, I get the following examples:

concealable armor
5 Armored Clothing I, covers 85% of arms, legs, torso, abdomen
7 Armored Clothing IIA, covers 85% of arms, legs, torso, abdomen
7 Vest IIIA, covers 85% of torso, abdomen
8 Armored Jacket IIIA, covers 85% arms, torso, abdomen

3 Helmet IIIA, 50% coverage
4 Helmet IIIA, 75% coverage (assumes face shield)

obvious armor
9 Vest IV, covers 90% of torso, abdomen
12 Full Suit (no helmet) IIIA torso, abdomen, arms, legs 90% coverage
14 Full Suit (no helmet) IV torso, abdomen, IIIA arms, legs 90% coverage

22 Turtleshell suit IV torso, abdomen, III head, arms, legs, 100% coverage

Which means that the lesser suits of SR4 armor aren't too bad, but the heavier ones seem a bit wimpy. The helmets are also slightly under-rated as head protection is ridiculously vital. Of course, armoring the face and neck are very difficult. In addition a heavy helmet gets taken off because it wears out your neck, so they can't weigh too much.
Interesting read. You need to get out more, but interesting read. =i)
Crusher Bob
Yes, and I practice with them four hours a day, so that when I meet a shadowrunner I can kill it. biggrin.gif

Next up armor penalties:

I'm not that happy with how armor penalties are implemented in SR4, the way it's currently implemented and armor penalty generally means a big penalty since the check for penalties is based on armor vs (body x 2) but the penalty itself is based on armor vs body. So I'll present some ideas for more in depth armor penalties.

The main problem with helmets is that they effect your perception, of course you can add techno bells and whistles to negate the penalties.
Light coverage helmet (35% of head)
using my above data: IIIA provides 2 armor
gives a -1 penalty to hearing (perception)

Medium coverage helmet (covers 50% of head)
standard infantry helmet: IIIA, provides 3 armor
gives -2 to hearing (perception)

Helmet with face shield (covers 75% of head)
riot/bomb squad type helmet, IIIA, provides 4
gives -3 to hearing and -1 to vision

turtleshell helmet (100% coverage of head and neck)
only worn as part of complete suit, otherwise too hard on the neck, but provides roughly 6 points of armor (class III)
-4 to hearing and -2 to vision

So, a standard infantry helmet basically doubles a soldier's ability to resist damage.

Armor on the torso and abdomen
Armor on these locations is not as penalizing as armor on the arms and legs. The main problem is getting hot.

Cloth armor (I or IIA)
no penalties

Flexible armor (II or IIIA)
-1 penalty on extended physical tests (climbing running, etc) without cool environment or techno/magic cooling system.

Semi-rigid (III)
cooling (as above) and a additional -1 on physical skills (as enhanced articulation)

Rigid (IV)
cooling penalty goes to -2, -1 on physical skills, -1 reaction

Arms and legs
Much larger penalties than on the chest:

Cloth armor (I or IIA)
no penalties

Flexible armor (II or IIIA)
Slight loss of flexibility and speed gives a -1 penalty to close combat tests

Semi-rigid (III)
-1 to both close and ranged combat

Rigid (IV)
-1 AGL, -1 cooling

Cloth armor (I or IIA)
no penalties

Flexible armor (II or IIIA)
-1 Physical Skills

Semi-rigid (III)
-2 physical skills, -1 close combat tests, -1 REA

Rigid (IV)
-1 AGL, -1 REA, -2 physical skills, -1 cooling penalty

So the totals for someone in turtleshell (IV chest, abdomen, III head, arms, legs) would be:
-3 cooling, -3 physical, -2 reaction, -2 close combat, -1 ranged combat, -4 hearing, -2 vision
Without an additional cooling system and perception enhancments it can present some real difficulties.

'open' heavy armor
(plus whatever penalties from the helmet)

Full Suit (no helmet) IIIA torso, abdomen, arms, legs 90% coverage
-1 cooling, -1 close combat, -1 physical

Full Suit (no helmet) IV torso, abdomen, IIIA arms, legs 90% coverage
-2 cooling, -2 physical skills, -1 reaction, -1 close combat

of the concealed armor I statted out above, only the armored jacket has any penalty, with -1 close combat.


The turtleshell suit might be a bit over the top, but them an HMG will go right through it.

Is this a though experiment or do you think that this is playable? Would you be willing to type out an example initiative pass pass with burst?
Very cool. It seems simpler than I remember CP2020 being and it translates easily back to SR3. I didn't see how 'cooling' affects the game, nor did I see you actually include rules for shifting damage based on hitting someone in a particular area. My big concern with this is if you have a 70% chance of dying when hit in the head with any sort of small arms, given the called shot rules as they are, I can only imagine people always shooting for the head, so the called shot rules will DEFINITELY need to be revised. This does bring up the potential for 'AVS burst called shot to the head, bypassing armor and upping damage, booyah HEADSHOT! lolol'
Be careful with the stats on the website you listed. These statistics are not combat related gun shot wounds. Those statistics included all self inflicted wounds too. Notice the really high percent of leg wounds? Also most firearm attacks are 1) perpetrated by someone the victim knows and 2) executed at close range (less than 15 feet).

You should look for military and police related statistics, these stats are just drunks and domestic abuse cases. Nothing here to base game rules on.
Crusher Bob
The hit locations of the wounds are tracked by type. The type I picked out was listed as assault/intervention. Self inflicted wounds are tracked seperately.
QUOTE (Crusher Bob @ Aug 7 2007, 11:05 AM)
The hit locations of the wounds are tracked by type.  The type I picked out was listed as assault/intervention.  Self inflicted wounds are tracked seperately.

True, but assault/intervention includes all drunks and domestic assault cases, you can't base game rules on that. You'll need military and police officer inflicted injury stats for game rules.
Crusher Bob
I used the data on table 8 of my second source to confrim the data I had.


  2nd source data hit %    my data hit %
 face              .22    
 cranium         .09
 neck             .03
 (head total)    .33             .283

 torso            .44            .43 (thorax + abdomen)

 limbs            21             .292

As for the 'cooling' penalties, some GM discretion is involved on when the penalty applies. The penalty itself I had intended to be on all physical skills linked to physical stats (opposite of enhanced articulation bonus). The general rule of thumb would be that any time an extended test is called for, the cooling penalty applies. So while it wouldn't apply for running accross the street (a single running roll), it would apply for chasing someone (several running rolls).
Oh, yeah. Encumbrance penalties. I'd forgotten about those. Suddenly, dermal plating and cyberlimb armor make a lot more sense.
The second source is awesome. Notice the radical difference between hit locations: in Vietnam, only 5% of small arms injuries were leg injuries versus the 33% of the drunk/domestic-assault cases listed in the other site.

I would think the Vietnam stats would be the ones to use because the Vietnam stats are segregated into Small Arms where the other conflicts lump in artillery with the small arms damage. Furthermore, jungle warfare would be most similar to postmodern urban jungle warfare.

Beware of the Northern Ireland stats and notice their really high percentage of lower extremity injuries? This is because the IRA was intentionally targeting kneecaps. The motto: "intimidate, kneecap, exile, or kill" the enemy. In fact, knee replacement surgery technology has surged partly because of that conflict alone. Here's a source:
I really like those optional rules. I've already revised worn armor in my SR4 games so the protection they give is more on par with the NIJ standards than the way the rules are currently written.

But going by these rules, how would you stat out the implanted armor (i.e. Dermal Plating/Sheathing, Orthoskin)?

Crusher Bob
[edits of value of IIIA armor, was an earlier revision numbers)

Here we start getting into things requiring actual game philosophy decisions.
I'm trying to make the system roughly similar to SR4's in the end, but so that you can see all the knobs and decisions that went into it, so that you can twiddle with them if that's what you want.

Hit locations and damage
How too represent hits to the head are much more lethal?
1st idea is as follows: assume hits to the thorax cause 'average damage' and the lethal % for hits to that area does a pretty good job in representing SR4 damage.

So we get:


location  lethal %  damage mult
head        70           1.37
thorax      51           1
abdomen    40           .78
arms        .01          .02
legs         .05          .1

Now, heres where the game design part comes in. I'd like to have damage multipliers such that the average SR4 damage will remain the same. So, if you do use the hit locations, your average damage will be roughly the same.

Using the data from the 2d6 hit table


location   hit chance  damage mult
head         .278           1.5
thorax       .278           1
abdomen   .167           1
arms         .083            .5
legs         .194           .5

Assuming you rolled on the 2d6 table and then multiplied by the damage, your average would be 1.0005 times as much as if you didn't. I not exactly happy with these (damage multiplier) numbers but they are simple, fit the math, and produce the same average damage. If someone else wants to try plugging in some numbers and come up with something that matches the first damage multiplier table, go right ahead.

Time to check some math:

We'll be shooting at Bob (body 3), who is wearing a standard infantry helmet (3 armor, IIIA, 50% of head) and a leopard print thong. We are using a rifle that does 6 (-1) and expecting one or two hits (we'll say 1.5)

So our average damage will be 7.5 with Bob rolling 5 dice to resist. This means he takes around 5.83 damage.

Using the hit location system:

Well, heres another game design decision point. Do we want to roll to see if the round hits the helmet, and then apply the full armor dice (18) or just give Bob armor X coverage dice for that location (in this case 9)? In either case, the average damage will be the same. Since the second way seems to result in less random PC death and requires less rolls, I'll use it. In addition, how do we manage damage multipliers? I'll go with armor comes first, then multiply damage, then roll body. This may be too much work; if I have time I'll check the math on both result later. crap, I've just realized that this might result in trolls arms and legs being bulletproof, so better roll body and armor together, then multiply any damage that gets through. So I'm now going with: roll body+armor to resist, any damage that gets through is multiplied.

So average damage to the head looks like:
Armor 9 Body 3 damage 7.5 (-1)
Roll 11 dice to soak, get 3.67 hits, 3.83 gets through, multiply by 1.5 to get 5.75 damage.
Then it's a matter of multiplying the hit location and the average damage together to get an average damage of 5.39. This might be accounted for by the fact that the AP value was of less use this way, since it was only good for the head.

So we'll double check with Bob in armored clothing (IIA, 85% coverage, everywhere but head)

In the abstract version, this is armor 7, in the hit location version, it's 10 armor (12 *.85) everywhere but the head.

The average abstract damage is 7.5 (-1) vs bod 3 armor 7. Rolling 9 dice to soak. and taking 4.5 damage.

Using the hit location system, the average damage is 4.75. But watch out! the damage to the head 9.75 points (7.5 (-1) vs (10 soak)) * 1.5. This means that poor Bob has a pretty good chance (roughly 28%) of taking 10 boxes right off the bat. The bob with just the helmet only took an average of 6.25 to the head, meaning that his chances of being killed outright are greatly reduced.
Crusher Bob
Since I have some spare time, I'll check the numbers for a much bigger gun (or the same gun being fired by a gun adept, assuming we'll keep hits add to damage).

Damage is 12 (-1) (6 (-1) plus six hits))

Naked Bob:
abstract: 11 damage
hit locations: 11.01 damage

Helmet Bob:
abstract: 10.33 damage
hit locations: 9.89 damage

Armored clothing Bob:
abstract: 9 damage
hit locations: 9.26 damage.

Interesting bits:
helmet Bob's chance of death is somewhere around 72%, because the helmet won't reduce the hits to the head to below a lethal level and hits to the thorax and abdomen are lethal as well.
On the other hand, Armored Clothing Bob will only be killed outright by a hit to the head, meaning that he has only a ~28% chance of instant death.

(ignoring dice variance in both of the above statements)

We'll also check turtleshell Bob vs the big gun:
(22 armor + 3 body)
abstract: 4 damage
hit locations: 3.89 damage
Does armor reduce the damage of an attack before or after multiplying it? That could save Helmet Bob.
Crusher Bob
Multiplication is after soak is done.

The damage for helmet Bob using hit locations for the head looks like:

He is hit in the head for 7.5 (-1)

He has body 3 and 9 armor on the head. So he gets 11 dice to resist 7.5 damage.
He gets 3.67 hits and is looking at 3.83 hits of damage, multiplied by 1.5 means he takes 5.75 points of damage.

Helmet Bob vs the Big Gun ™:
He is looking at 12 damage, getting 3.67 hits on soak, leaving 8.33 damage for multiplication, which turns into 12.5 damage. Ouch!

You have to multiply the damage after soak, both the save the head and to prevent the arms of trolls from being bulletproof.

Buff troll (body 15) is shot in the arm with an anti-material rifle (8 (-12) damage) and 4 successes. He is wearing no armor on the arms. If the damage was multiplied before soak then the damage would drop from 12 to 6 and he would soak 5 of it. Doing it the other way, he soaks five, leaving 7 damage, then multiplied to 3.5 damage.
I have always questioned the need for hit location (or an extensive called shot system) in games like shadowrun that already have a degree of success defect on damage. Since we also have a called shot to avoid armor rule this is doubly redundant.
I have seen systems with mead use of a similar system but they where much less complex otherwise than shadowrun. Warhamer fantasy roll play comes to mind, where armor provided a fixed protection value but only covered sertan portions of the body. Shadowrun is more fast paced (theoretically) and actions take longer to resolve.
Crusher Bob
Bullets and armor penetration. (When to convert to stun?)

This one is a bit harder. There's no real way to show my math on this one, since it was largely randomly manipulating numbers in excel until I got something that looked about right.

One of the main problems is differentiating the much greater penetration of rifle rounds vs pistol rounds.

So, my recommendation is as follows:

All rifle rounds are modified by subtracting one from their base damage and adding 4 to armor penetration values.

Using SR4 stock weapons, this gives us the following:


Weapon        Damage      AP value     Penetration Total
Light pistol      4                 0                4
Heavy Pistol      5                 1                6
Very Heavy P      6                 2                8

Assault Rifle     5                 5               10    (was 6(-1))
Battle Rifle      6                 6               12    (was 7(-2))

This lets the concealable armor stop pistol rounds but you need one of the heavy suits to convert rifle rounds to stun. If you are using the hit location system, then then checking the penetration vs 1/2 armor after subtracting the AP value seems to produce results that are somewhere in the right neighborhood. For example, class III armor (21 dice) providing 90% coverage gives an armor value for that location of 19. Shooting at it with a battle rifle (6(-6)) means that after AP, you are looking at 13 armor, halved to 7. which means that the round would be converted to stun with one success to hit, and be physical damage for 2 or more successes.

In general, very heavy weapons should be modeled by having a very high AP value, while the actual damage value is kept under control. So the assault cannon in SR4 (10(-5) Pen total 15) is probably better modeled as (8 (-12) Pen total 20). This prevents you from rolling as many dice when someone shoots at a citymaster, but still lets you have a big pile of armor on it.

No magic bullets
I really dislike how SR4 models it's bullets. The each cost several nuyen.gif and have a large effect on how well you damage the target. Bullets should be cheap, and it's the weapon and your shot placement that should provide the majority of the effect.

Standard rounds:
All standard rounds are assumed to be full metal jacketed (FMJ) rounds. They provide a compromise between tissue damage and armor penetration.

Expanding rounds:
These rounds provide increased tissue damage at the expense of greatly decreased performance vs armor.

Effect: +1 damage +4 AP value.

Against armored targets, these bullets do worse, against unarmored targets you get a large bonus. With the advent of cheap and common personal armor, only hunters really use this type of bullet.

Armor piercing:
These rounds provide increased armor penetration, but the lack of bullet deformation
reduces damage to tissue.

Effect: -1 Damage -4 AP value.

When shooting someone in armor, these rounds provide a small advantage. However, it is easy to do without.

The price of bullets drops to something like 25 nuyen.gif per box of 100 pistols rounds and 50 nuyen.gif per box of 100 rifle rounds.

Due to their greater mass, shotgun loads may require special rules. Will think about it later.
QUOTE (Crusher Bob)
One of the main problems is differentiating the much greater penetration of rifle rounds vs pistol rounds.

So, my recommendation is as follows:

All rifle rounds are modified by subtracting one from their base damage and adding 4 to armor penetration values.

First of all, the whole point of using a code block is so that you can get your columns formatted all nice. You might want to clean that table up a bit. smile.gif

Also, I'm confused by what you're doing here. According to your stated goal, shouldn't you be lowering their AP value so that they penetrate better?
Crusher Bob
My intention was that the assault rifle goes from 6(-1) to 5(-5). Firing AP bullets out of your assault rifle makes it 4(-9) and firing expanding bullets makes it 6(-1) again.

Firing AP bullets out of your predator makes it 4(-5) and firing expanding bullets makes it 6(+3).
Okay. That's what I thought you meant.

It seems reasonable. I'm not sure how valid of a measure your "penetration total" is. Obviously a point of AP is not worth a DV, so simply adding them together isn't really a great measurement. If you're looking for expected damage against an armored foe, AP should really only contribute 1/3 as much to the consideration as DV, and against an unarmored foe it's worth even less. (nothing, in fact) So "penetration total" can be a bit misleading. I think a better metric would be DV-(AP/3).

Which brings me to my other question. Why are you trading 1 DV for 4 AP? Granted, the 4:1 trade-in rule sets a bit of a precident for that, but I would think that in this case you'd want to use the statistically expected values for a 3:1 trade-in. By doing a 4:1 trade-in, if you decrease DV by 1 but improve (see how I cleverly dodge the increase/decrease issue? wink.gif ) AP by 4, then the expected damage against an armored opponent increases by 0.33 boxes. Of course, not everyone will be armored, but considering the ubiquity of armored clothing I'm not sure how carefully we need to be considering the unarmoed foe. I mean, if you assume that 1/4 of all foe's will be unarmoed then the expected damage breaks even, so maybe a 4:1 trade-in is good.

All in all, I have no objections. It seems like it accomplishes your desired goal nicely.
Crusher Bob
The penetration total is listed so that you can do quick checks on what kind of armor will convert it into stun. Before the penetration total of heavy pistols of 6 and assault rifles od 7 meant that an armored jacket would stop both rounds (assuming not too many successes). With the modified values, assault rifles have a penetration of 10, meaning that concealable armor will basically never convert assault rifle fire into stun.

I gave the rifles a 'free' extra point of AP because I think that SR greatly shortchanges the greater penetration of rifle fire.
QUOTE (Crusher Bob)
The penetration total is listed so that you can do quick checks on what kind of armor will convert it into stun. Before the penetration total of heavy pistols of 6 and assault rifles od 7 meant that an armored jacket would stop both rounds (assuming not too many successes). With the modified values, assault rifles have a penetration of 10, meaning that concealable armor will basically never convert assault rifle fire into stun.

I gave the rifles a 'free' extra point of AP because I think that SR greatly shortchanges the greater penetration of rifle fire.

Ahh, see, I was misunderstanding the point of the penetration total. I got it now. Good point.

Thanks for clarifying that.
Sounds good, all around.
Crusher Bob
Armor and weapons:

1 Concealable armor covers less area than obvious armor of the same type. So obviously armored clothing (think armored uniform) might provide a bit more actual armor value than concealable armored clothing.

2 Calculating the exact coverage of armor is difficult since bullet wounds are not completely randomly distributed over the target area. Covering the right 25% of the surface area might provide 50% coverage in the armor calculation.

3 Armor that is 'open' is incapable of providing 100% armor coverage, shots from the side, top, etc still have a chance of getting through. Should there be an extra penalty for closed armor, on top of other armor penalties?

4 Helmets are generally rated for IIIA (good vs all pistols) protection. Helmets that provide more protection are difficult to make, both because class III and IV armor are considerably heavier and the physics of providing heavy armor to the head are somewhat more complicated.

Light Helmet 35% coverage (2 armor, -1 to hearing tests)

Standard Helmet 50% coverage (3 armor, -2 to hearing tests)

Helmet with face shield 75% coverage (4 armor, -3 to hearing tests, -1 to vision tests, -6? to enhanced smell)

Closed Helmet (turtleshell type, only worn with full sit of closed armor) 100% coverage (around 6 armor, but is factored into full suit armor) (-4 to hearing, -2 to vision, enhanced smell useless)

Concealable armor
In order of descending concealability:

Light concealable vest: armor 4
worn under clothing
Class IIA, 75% coverage of thorax and abdomen

Light armored clothing: armor 5
(armored hawaiian shirt and armored shorts)
Class IIA, 65% coverage thorax and abdomen, 33% coverage arms and legs

Armored clothing: armor 7
(fully covering clothing such as a business suit)
Class IIA, 75% coverage of thorax, abdomen, arms, legs

Concealed Vest: armor 7
Class IIIA, 85% coverage of thorax and abdomen
-1 cooling penalty
An alternative to the armored business suit. You don't have to keep up with the style. On the other hand, you sweat a lot.

Armored Jacket: armor 8
Class IIIA, 85% coverage of thorax, abdomen, arms
-1 to close combat tests, -1 cooling penalty

Unconcealable Armors
Armored Fatigues: armor 8 [edit, was 9, mistake in excel file]
Class IIA, 90% coverage of everything but the head.
(Protects against shrapnel and greatly increased your odds of being presentable enough for an open casket funeral, what more could you ask for?)

Armored ninja suit: armor 10
Class IIA, 75% coverage of head, 90% coverage of the rest of the body.
(If you plan on sticking on a helmet, use the base value for armored fatigues instead)

Light full armor: armor 11 (no helmet)
Class III, 90% thorax and abdomen, IIA 90% arms and legs
-1 cooling, -1 physical skills

Heavy Full armor: armor 14 (no helmet)
Class IV, 90% thorax and abdomen, IIIA 90% arms and legs
-2 cooling, -2 on physical skills, -1 reaction, -1 close combat

Turtleshell: armor 22 (includes helmet)
Class IV, 100% thorax and abdomen, III 100% arms and legs
-2 cooling penalty, -3 on physical skills, -2 reaction, -1 on both close and ranged combat tests, -4 hearing, -2 vision, enhanced smell useless.

Of course, such a suit would have a cooling system, and all sorts of sensory enhancements tacked on...


There are all sorts of gameable holes in the way I've calculated the armor values. Best not let the players loose on them. For example, wearing bullet resistant (Class I) panty hose pulled over your head (a CP2020 favorite!) would give you around 2 points of armor!


Well, they are putting up the typhoon signal here in HK, will be back with the weapons in a bit.
Crusher Bob
Next on to weapons and making sure the numbers match up right.


Weapon Type          Damage        AP
Light Pistol             4            0    (9mm)
Heavy Pistol             5           -1   (10 mm)
V. Hvy. Pistol           6           -2   (44 mag)

Assault Rifle            5           -5   (5.56 NATO)
Battle Rifle             6           -6   (7.62 NATO)

Sniper Rifle             6           -8   (300 win Mag)

Anti-Material Rifle      8          -12    (.50 BMG)

Concealable Armor (armored clothing (7), body 3)
1.5 net hit on the attack

Heavy pistol
Damage 6.5 (-1) vs soak 10 (damage converted to stun 1/2? the time)
taking 3.5 damage per hit

HP with AP Ammo
Damage 5.5 (-5) vs 10 soak (damage never converted to stun)
taking 3.83 damage per hit

Single AR round
Damage 6.5 (-5) vs 10 soak
4.83 damage per hit

Single AR round, AP
damage 5.5 (-9) vs 10 soak (still rolls 3 dice, only had armor 7)
4.5 damage per hit

[heh, bonus! AP ammo is not always the best thing to load into your rifle.]

Obvious armors:
Armored Fatigues + helmet (11 armor + body 3)
1.5 net hit on the attack

Heavy pistol
Damage 6.5 (-1) vs soak 14 (damage converted to stun)
taking 2.17 damage per hit

HP with AP Ammo
Damage 5.5 (-5) vs 14 soak (damage converted to stun)
taking 2.5 damage per hit

Single AR round
Damage 6.5 (-5) vs 14 soak (converted to stun 1/2 the time)
3.5 damage per hit

Single AR round, AP
damage 5.5 (-9) vs 14 soak (damage always physical)
3.83 per hit

Heavy suit + helmet (17 armor)

AR burst 8.5 (-5) vs 20 soak (damage always stun)
3.5 per hit

AR AP burst 7.5 (-9) vs 20 soak (damage always stun, but right at the limit)

Battle Rifle AP 6.5 (-11) (converted to stun half the time)
3.5 per hit

Anti-material rifle 9.5 (-12) (always physical)
6.83 per hit


Possible rules addition:
Stun damage is soaked with Body + Will.
This way, you really want to be carrying around something that will penetrate the other guys armor. Note that melee combat would need to be changed to account for this.


Fixing the slivergun

Damage 2 (-cool.gif
24 round magazine
gas vent/2

Slivergun ammo is always treated as AP ammo (already factored into the damage code).

This gives it great armor penetration, and it an interesting thing to carry around but dosen't seem too overpowered.
Eryk the Red
I'm not really into injecting bonus realism into my Shadowrun much, but this stuff is actually really neat. If I were to start a new campaign, I'd likely modify the weapon stats based on this stuff, simply because it makes them more interesting.

(I wouldn't likely add the hit location stuff, because I don't want to make more work for myself during combats.)
Crusher Bob
I'm not really advocating the hit location system either, but created the system to expose more 'design knobs'. This way, if someone decides they want to alter the system further, they can take a look at all the bits that went into making it.
Eryk the Red
I never really understand why the RAW weapons all have such weak AP values. There's room for greater weapon variation, but instead you just have this progression of "higher DV and better AP". I like this way better, where a rifle might have a close DV to a pistol, but much better penetration.
Crusher Bob
Vehicles and armor:

How much armor should that vehicle have?

Are the weapons modeled right so that the right kind for feel is preserved?

In general, people measure vehicle armor as the amount of
rolled homogeneous armor (RHA) it is equivalent to. While anti-vehicular weapons are likewise measured by the amount of RHA that they can penetrate.

Sample armor thicknesses:

Armored limo/executive protection style armored sedan: 9-12mm RHA (good vs pistols and some rifles)

Cash transport type armored car/armored humvee/police type armored vehicle: 15mm RHA (good vs rifle fire)

Lightly armored APC (M113) 25mm RHA

Heavy armored APC/IFC (Bradley, BMP3) (40+mm RHA front, 30+mm Sides, 25mm Rear)

Light Tank/Armored car/Obsolete MBT (200+mmRHA front, 80+mm RHA sides, 25+mm RHA rear)

Modern MBT (600+RHA front, 200+mm RHA sides, 80+mm RHA rear)

Armor penetration of bullets:

SS109 5.56mm (probably armor piercing in SR4) 12mm

M993 7.62mm AP 18 mm

12.7x99mm (50 BMG) (Heavy machinegun and Anti-material rifle round) 19+mm


It looks like we got luck and we can approximate the amount of RHA that a bullet in SR4 will penetrate by comparing it's penetration total (damage - ap value) to mm in RHA. This highly overrates pisotl rounds, but the rifle rounds and the HMG rounds seem to be in about the right place.

Once you get higher that HMG rounds in your SR game, you are probably better off just not rolling damage.
QUOTE (Crusher Bob)
Vehicles and armor:

How much armor should that vehicle have?

Meh, I think there's really a problem with the way hardened armor works in SR4, which makes any further considerations weird.

(this has been gone over many times, but a quick review for anyone who hasn't seen it)
For illustrative purposes, let's imagine a target with Body 12 and Hardened Armor 24. This could be a force 12 spirit, or a citymaster-like vehicle, or whatever.
If you put a modified DV of 24 or less against this thing it takes 0 damage.
If you put a modified DV of 25, it gets an average of 12 hits, and takes 13 damage against it's damage track of 14 boxes.

It is either fine, or dead. Now maybe that's a feature, not a bug. Maybe beefy spirits and tanks should ignore anything that doesn't kill them. Maybe that's realistic (at least in terms of the vehicles), but I really don't know. Realistic or not, it would probably be good for the game system if these targets could take damage that didn't flat-out destroy them.
Eryk the Red
I haven't done the math, but I think weapons with significant AP values have a better chance of doing damage that doesn't destroy outright. And if you re-stat weapons in the way that's been discussed in this thread, it might work alright as is. But someone would have to do the math to figure that out.
QUOTE (Eryk the Red)
I haven't done the math, but I think weapons with significant AP values have a better chance of doing damage that doesn't destroy outright.

You're absolutely right. Because it's a problem that occurs with high hardened armor values, so good AP is going to lower the armor value.

Rules which increase AP values (overall or for some weapons) will push this problem farther away. They don't eliminate it, but they might well push it far enough away that it's not a problem.
Crusher Bob
Firing AP HMG rounds (7 (-16)) at an APC
[edit, sigh had to reduce APC armor to 24 so that a single round would get through]
(24 armor, 12 body):
1 round with 1.5 hits
Damage 8.5 (-16), leaving 8 armor
20 dice to soak get 6.67 hits, leaving 1.83 damage.

Same round vs armored limo
(armor 12, 6? body)
damage 8.5 -16, leaving no armor.
6 soak dice get 2 hits, damage 6.5

The trick is to have the actual damage value take only a fraction of the penetration value. This makes it more survivable for characters, means that you roll less dice when you actually have to soak something, and lets you control damage vs armor a bit better.

Sample LAW vs light armor
The M72 LAW penetrates something like 350mm RHA. If we bothered to give it a damage code something like 35 (-315) might do.

The APC is toast (taking 32.5 damage) [edit here, was 34.5]

A light tank with 300mm RHA on the front and around 36 body (has 26 hits?).
The AP value of the LAW negates the tank's 300 armor on the front, leaving 36.5 damage to be soaked by 36 body. The tank gets 12 hits and takes 24.5 damage.

Second light tank
The enterprising tankers have added some sandbags to the front of the tank, being worth another 50mm of RHA vs HEAT rounds.
The LAW barely penetrates (penetration 351.5 vs armor 350). The extra armor gives the tank another 35 dice (350 armor - 315 AP value = 35) to roll for resistance. This means that the tank only takes around 12.83 damage.

LAW vs side of MBT
We'll give our MBT armor 300 on the side and 60 body. (38 hits?) So we are looking at 36.5 damage vs 60 soak. The tank takes 16.5 damage.

While this is not really ideal, it probably models heavy vehicles and weapons good enough for most SR games.

[edit 2, will throw in tank gun vs. tank's frontal armor]
Tanks frontal armor 600, body 60, condition monitor 38 hits

Tank gun (penetrated 650mm RHA) 65 (-585)
Hits with 1.5 successes.

Damage 66.5 vs body 60 + 15 armor (75 total soak, 25 hits on soak). Tank takes 41.5.

From a longer range band, the tank gun only penetrates 600mm RHA (60 (-540)
With 1.5 hits, this is still enough to penetrate the tank.

Damage 66.5 vs body 60 + 60 armor (120 total soak, 40 hits). Tank takes 26.5 damage.
Crusher Bob
Some more in depth numbers, to be sure that things are working out:



Vehicle              Body         Armor     Condition monitor
Regular Sedan          4                          10
Armored Sedan          4             9            10
Regular Limo           6                          11
Armored Limo           6            12            11
UPS Van/Truck Rig      8                          12
Armored Van            8            15            12

Light APC             12        24/24/24          14
Heavy APC             18        48/30/24          17
Light Tank            36        300/150/60        26
MBT                   60        600/300/100       38

The heavy vehicles have armor listed as front/sides/rear

Assume top and bottom armor are somewhere between the rear and the side armor in depth.


Weapon                           Damage  AP value   Pen total
Heavy Pistol (AP rounds)            4      5            9
Assault Rifle/LMG (AP rounds)       4      9           13
MMG/Battle Rifle (AP rounds)        5      10          15
HMG (AP rounds)                     7      16          23
Anti-Armor Launched Grenade        12      36          48
Autocannon                         15      45          60
LAW/Light ATG/Light ATGM           35      315        350
Tank Gun                           65      585        650
Heavy ATGM                         75      925       1000

Sample data:
Light APC vs autocannon
damage 16.5 (-45) vs armor 24 body 12 soak 12 dice, getting 4 hits, taking 12.5 damage. Short burst to destroy.

Heavy APC vs autocannon
damage 16.5 (-45) vs armor 48 body 18 soak is 21 dice, getting 7 hits, taking 9.5. 2 shots or long burst to destroy the Heavy APC.

Light tank (rear armor) vs autocannon
damage 16.5 (-45) vs armor 60 body 36, soak is 51 dice, getting 17 hits, taking no damage unless a burst is fired or the attacker gets more hits. Assuming a full burst is fired (+9 DV) then it would take around 3 to destroy the tank.

MMG vs van
damage 6.5 (-10) unarmored van has soak 8, takes 3.83 damage.
Armored van has soak 13, takes 2.17 damage

AR vs armored police car
damage 5.5 (-9), police car had 4 dice to soak, takes 4.17 damage
Note: Unarmored sedan takes same damage.
Had we been using FMJ AR rounds (5 (-5)) the armored police car would have taken 3.83 and the unarmored sedan 5.17 damage.

Some fine tuning of the numbers would have to take place, but seem to offer some variation of damage that penetrates armor.
Crusher Bob
If you want additional complexity in heavy weapons then we need to account for some additional stuff:

Penetration decrease over range
The armor penetration of KE based weapons decreases significantly over range. Of course, this generally only matters for targets significantly further away than 500 meters...

HEAT resistant composite armor/Explosive reactive armor
If you are going to model the extra HEAT resistance of composite armor/ERA then you'd need to fiddle with the damage of the HEAT based weapons some.

As a sample, the MBT with composite armor would rate something like 1200/600/200 vs HEAT attacks and 600/300/100 vs KE attacks and an ERA equiped MBT might have an extra 300mm RHA equivalent on the front.

If you are going to do that though, you'd need to model top attack and tandem charge attacks... and most people will not be interested in that kind of detail.
Crusher Bob
Heh, can't let my wanking thread fall off the first page. smile.gif If any of you are reading, please weight in on some of the system questions.

Should stun damage be soaked with BOD + WIL? There should be some 'penalty' for having damage converted to stun, but how to implement it?

Did anyone want more complex modeling of heavy vehicles and their armor?

Any gimmik weapons you'd want to see modeled? (HK MP7? .458 SOCOM?, 5.56mm Steyr Flechette?)

We'll use as our two points for comparison 7.62 NATO firing expanding rounds 7(-2) and 50 BMG 8(-12). Buckshot rounds produce massive injuries, so we'll start with a base damage of 8, but buckshot won't penetrate armor very well. AS the heavy pistol has a penetration value of 6, we'll guess buckshot should rate around a 5. This would make buckshot do 8(+3). This makes shot mostly useful for killing unarmored targets and blowing doors open.

Shotgun slugs.
We'll give slugs a base damage of 7. It looks like IIIA armor will stop most slugs which implies that the total penetration of slugs should be no more than 9. If we give slugs an armor penetration of (-2) that would make the final damage code 7(-2) making them generally identical to expanding 7.62 NATO (but have a much shorter range). This doesn't fell quite right, but there not a whole lot of wiggle room left in the numbers.

Buffalo rifles
Since they included the elephant gun in the basic equipment list of SR4, better come up with some numbers here. Since 50 BMG does 8(-12) we'll stat up the buffalo rifle as doing 8 but having much lower penetration. 8(-3) might do the job.

This one will present some difficulty. Armor provides significant protection from shrapnel, which means that someone in any of the armored suits would be highly resistant to any shrapnel based attack. In addition, there's the game mechanics worries about how to reflect successes to hit in increasing grenade damage.

In addition, there is a significant difference between the power of hand grenades vs launched grenades. (The hand grenades are considerably heavier, packing more explosives and more fragments).

So I'll try to model three different sizes of grenades:
Hand Grenade
Fragmentation type
Damage 12(+6) -1 damage/meter
Offensive/Concussion type
Damage 10 -2 damage/meter
Large launched grenade (40mm)
High Explosive Dual-Purpose type
vs armor: 12 (-36) (direct impact vs vehicle)
+ fragments 10 (+6) -1 damage/meter
Small launched grenade (25mm)
All the multi-round underbarrel GLs fire this type.
High Explosive Dual-Purpose type
vs armor: 9 (-27) (direct impact vs vehicle)
+ fragments 8 (+6) -1 damage/meter

This means that grenades have greatly degraded utility vs anyone in heavy armor (14-17 dice) will be highly resistant to grenades.

As a quick fix for resistance to grenades vs placement, I'd try explosions are soaked with BODY + REA as long as you have the ability to get out of the way (are not restrained or surprised). Adding movement modifiers may also be worth a look: so target was running +2, target was walking +1 (penalty for being stationary?). And bonuses for having the grenade going off on the other side of the cover you are behind (+1 to +6).

Helmet Bob (armor 3, body 3, reaction 3) is hiding behind a wall (cover +4) when a grenade goes off right on the other dice. he 12 damage with body 3 + rea 3 + cover 4 + armor 9 for a total of 19 dice. This gets him around 6.33 hits, meaning he takes 5.67 damage. Had he been in the open, he would have only rolled 15 dice for soak and taken 7 damage. Had he not been wearing hit helmet, the damage would have gone up by another 3 points.

A Bob in heavier armor (total armor 14) in the same situation (behind cover) would have only taken 2 points of damage.

This may weaken grenades a bit too much (especially compared to area of effect spells), so some more tinkering is warranted. Any suggestions?
Eryk the Red
About Body + Will resisting stun, I don't think that should be the blanket rule. I think Willpower should add to damage resistance when armor is not penetrated. (Whether the damage was originally Stun or Physical.) This is a game balance preference, more than anything.
Crusher Bob
Hmm, how about just reducing the damage by 1 point if it was converted to stun? Keeps you from needing to roll anything and makes the change in damage specifically part of the 'convert to stun' process.
Feel free to model the MP7.

I really need to see if I can legally purchase one in RL. Might have to special order it such that it's modified to not support FA.
Crusher Bob
Might as well model the whole family os such arms

Starting with the slivergun replacement

All assumed to be firing AP ammunition already. If you want to implement velocity control for silencer, the performance drops through the floor (reduce AP value by 6 or so).

damage 2 (-8)
magazine 24 rounds
gas vent/2

machine pistol
(HK MP7)
damage 2 (-8)
magazine 40 rounds
Intergral 2pts recoil comp?

sub-machine gun
(FN P90)
damage 3(-8)
magazine 50 rounds
Intergral 2pts recoil comp?

Assault Rifle
(steyr ACR )
Damage 3 (-13)
(hmm, what to give it for mag capacity)
magazine 60? rounds
Intergral 2pts recoil comp?

The ACR is the real loser here, you have to be shooting at someone in heavy armor for it to do better than a basic assault rifle.
Hey Bob, got some info for ya...

Per the manufacturer website the MP 7 only does SA & FA. It also supports 20 and 40 round magazines.

Also, saw a demo of it on Future Weapons and it penetrates NATO standard armor with the standard ammo (4. something mm rounds). In fact, the helmet he was shooting at, the round penetrated the front of the helmet and exited the back. Exit hole was about the size of a quarter (25 cent coin).
Crusher Bob
These are not exact copies of the real world guns. I gave all of them the SA/B/FA option since SR does not allow firing short bursts from FA only weapons. THe helmets are only rated as IIIA armor. Since the MP7 has penetration stats that are the same as an assault rifle (both are pen 10) it will also penetrate the helmet.

Since SR4 does not have complex concealability, modeling the 20 round magazine for the MP7 like weapon doesn't have much point. Using the shorter magazine won't make it as concealable as a heavy pistol, so why bother?

I'll throw in the various integrally silenced weapons as well:

Assault Rifle
(.300 whisper)
Damage 6(-2)
magazine 30 rounds
Intergral 2pts recoil comp?
Sigh, SMG ranges are too short, but maybe you should use them instead of AR ranges.

Sniper Rifle
(VSSK or .50 whisper rifle)
Damage 7(-4)?
magazine 5 rounds
Use assault rifle ranges
Crusher Bob
Evolution in armor and weapons.

One of the problems you'll run into designing games set in the future is that the systems you develop are not 'fully evolved'. So some weapons don't have a counter, or some armor is unbeatable, or some clever combination of stuff from thing X and thing Y giv you an unbeatable advantage.

You can see the evolution of weapons systems pretty clearly if you watch things. For examples, the development of the Wild Weasel doctrine to counter SAMs deployed in Vietnam.

An additional problem in game design is that you never want the character to become determined only by the equipment he carries. So, we don't want the combat in the game to revolve around who has the latest series of combat nanites, with whoever doesn't being killed so fast that they didn't even have time to notice their death.

The other game design problem is that certain things are quite difficult to model without every player having an in depth knowledge of the actual thing being modeled. See for example, and in brief guide to BVR (beyond visual range air to air) tactics try A nuggets guide for a quick sampler (look for the section that starts with when to use the Jammer).

So, for example, how do you address stuff like composite armor (chobham) and its relatives), top attack ATGMs, active anti-missile defenses (Arena and it's relatives), electrical/capcitor based anti-HEAT systems, or whatever the newest thing is? They'll have those in the future, right?

Remember that your final system has to be gamable. Unless you want to spend all your time thinking of all possible uses for a tech and it's counters, you either reduce it to two opposing rolls of the dice or just leave it out.

If you can find it, The old game Prefect from FASA has a pretty good sample of thinking about the ramifications of the technology. There's a bunch of neat stuff about how to fight with armies of flying tanks that you can drop from orbit, and some other stuff.

For a look at the 'just reduce it to opposing dice school' take a look at how Dirtside II (available here for free) handles missiles and missile defenses.

So how about composite armor?
The unit database in Tacops4 gives you some reasonable data for the RHA equivalent values of tanks equiped with both composite armor and ERA panels.

Assuming our sample tank of 600/300/100 was equiped with composite armor, giving it the 1200/500/150 vs HEAT attacks would no be out of line. While adding ERA panels to the front might give it 900 RHA equivalent vs HEAT. (much better data can be had out of the tacops unit DB).

So what about top attack missiles?
Currently, the top attack missiles are much newer than the tanks. This means that the current generation of tanks was not designed with top attack missiles in mind.

Sign, have some stuff to do, will come back later.
Hi Bob

Just like to say that this is just what i'm looking for my game. Been using hit locations for a while now and this ties in very nicely.

Especially like what you have done with the heavier vehicles and the weapons to take them out, as there was a huge problem with them under current game mechanics (not a scratch or Dead no in between).

Great set of house rules.

Have you thought about melee combat and impact armour? I see you are now using ballistic armour for resisting grenade damage.

First off, sorry for reviving an old thread.

Bob, have you done any more work on this idea, specifically:

Have you put any thought into using this system with melee weapons and hand to hand in general? Would you keep a separate impact armour rating system.

At first i thought you could get rid of impact armour all together, but on reflection there are real world armours that are very effective against knives, and also padded armour for use against batons that would not stop any but the lightest bullets.

I;ve been using these rules with my own hit location system for a while know and it seems to be working really well. I love the way you've modeled vehicle armour and anti-vehicle weapons.

If you have any more musing's on this subject i'd love to hear them.

Have you seen the AA 12 shotgun, and the various ammo it fires?

QUOTE (WearzManySkins)
the AA 12 shotgun, and the various ammo it fires

Wow! Now that kicks serious butt. There's a way to clear a room full of trolls..
@Redjack and Bob
OK here is some shots of the Kriss Prototype .45 cal SMG

FFS people... go outside, get laid...

Here's my math to contribution:

GM says "Yes, you can hit that location." 100% probability for a called shot.
GM says "No, you cannot hit that location." 0% probability for a called shot.

Great work however, and I'll prolly end up using it once or twice, heh. nyahnyah.gif
Wounded Ronin
QUOTE (nezumi)
Very cool. It seems simpler than I remember CP2020 being and it translates easily back to SR3. I didn't see how 'cooling' affects the game, nor did I see you actually include rules for shifting damage based on hitting someone in a particular area. My big concern with this is if you have a 70% chance of dying when hit in the head with any sort of small arms, given the called shot rules as they are, I can only imagine people always shooting for the head, so the called shot rules will DEFINITELY need to be revised. This does bring up the potential for 'AVS burst called shot to the head, bypassing armor and upping damage, booyah HEADSHOT! lolol'

Dammit, I almost feel like this thread should have been in the General Gaming thread because this info is useful for practically all games that have firearms and shootouts.

Anyway, in a simulationist setting the idea is to "balance" things by making them realistic. So I would just make headshots suitably unlikely. Of course, I suppose you'd also need rules then for randomly and unluckily getting hit in the head when the guy was aiming for the body, or during the course of suppressive fire.

Finally, if you don't want your pwecious PC to get headshotted just go around wearing a helmet with a ballistic faceplate. Not only would it prevent headshots from necessarily one-shotting you but it would provide endless hours of role playing enjoyment to the table as everyone in the game world looks at you strangely for going around all the time with that gigantic helmet.
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