Jump to content

Firearm-rules in BRP


Trifletraxor

Recommended Posts

It may be time to refine and define the question(s) better. It may also be time to move this to its own thread.

1) A review. In discussing possible design sequences for BRP it was put forward by me that firearms have anomolies compared to other games that rely on RW data and not on the needs of the designers. Specifically that pistols are overpowered compared to rifles and that damage done by other long arms seems to follow no rhyme or reason.

2) Point made that it is within current pistols' game capabilities to supply a major wound that will stop a human target.

2a) Point made that in BRP it is hard to kill humans with pistols in the game at least in one shot.

3) First thing to decide- Is the goal to kill (bring to 0 HP) or stop (render incapacitated) a human target? RW data looks at stopping a target. Shot at, stopped, and still living is the norm in armed conflicts. This is because there are many ways targets are stopped. Physical force, pain, psychological stresses, and disorientation are some of them.

I would opt for stopping a human target to be the reality check here.

It has been pointed out that as in real estate the primary concern in wound ballistics is location, location, location. ;) However even this is not as straight forward as we would like (is anything as complex as this ever straight forward?).

The concensus in the wound ballistics community appears to be that stopping a human can happen several ways.

Disorientation by the firing of the gun. Bright flash and loud noise actually stunning a person and rendering them incapable of action for a time.

Pain from an otherwise non-life threatening wound causing the target to be incapable of continuing. No structural damage (ie to organs, arteries or bones), just pain.

Damage to the body resulting in bleeding or loss of pumping efficiency. Deprived of freshly oxygenated blood the target will faint soon and then bleed out.

Damage to the central nervous system that results in unconciousness, paralysis, or death. Bullets stretch and pull on surrounding tissue creating temporary cavitation. A bullet does not have to hit the spine for instance to jar it hard enough to affect the spinal cord.

Bullet/body interaction are complex but I think that what needs to be modeled are targets' reactions to having small bits of metal forced through their body at high speed.

We see examples where round after round is fired into a target to no avail.

Apparently the rounds are not hitting organs,arteries, bones, or the CNS. In game terms the targets HP need to be ablated.

We see examples where an underpowered round drops a target. Apparently it did affect organs, arteries, bones, or the CNS. Currently we can not get this result in BRP/CoC.

I am currently working out a system where the target takes the HP damage but rolls d20 vs CON or HP in a location to avoid being dropped by damage to the CNS, which is after all a distributed system. I chose CON as a representation of the toughness of the tissues and to link it to the target. Same idea can be applied to determining damage to organs, bones, and arteries by rolling d20 vs POW which would determine bleeding. I am working out simple modifiers for hit location (currently limb, torso, and head) as well as the amount of damage to those locations modifying the roll (limb- none, torso- damage).

A point of damage from a .22 to a limb is very survivable. Roll vs CON to continue to act.

A 5 point shot to the torso. Roll d20 vs CON-5 to avoid incapacitation

A point of damage from a .22 to the head. Roll vs the HP in the head (CON/3 if you don't want to use hit location HP). If you make it no incapacitation. If you fail you drop and go unconcious.

If that is to complex then you could abstract the ability of firearms to incapacitate by rolling d100 vs 5x(POW-damage).

Success- take HP damage.

Fail- take damage and incapacitated.

Fumble- Take damage, incapacitated, and bleeding.

Use POW because hitting the CNS is more luck than anything else at this level of resolution.

Oh yeah do this for each round that hits. Multiple shots gve multiple chances for incapacitation.

I need to run some numbers on this stuff to see how it performs. It should allow pistols to be effective at stopping a human target with out requiring them to be overpowered in relation to other weapons.

Joseph Paul

Some alternate rules for the wiki on the way? ;)

Ef plest master, this mighty fine grub!
b1.gif 116/420. High Priest.

Link to comment
Share on other sites

  • Replies 115
  • Created
  • Last Reply

Top Posters In This Topic

Interesting, but I7d say use POW or CHA to continue acting rather than CON. It really isn't so much a question of your health, but of you determination.

CON would be used to survive or heal from the injury.

What I7d like to use is a delayed fatality/bleed to death rule. Something like a injury will inflict another point of general HP damage every (CON-DMG) minutes. Or maybe use a DMG vs. CON of resistance chart.

DMG Result

CS=1hp/SR

SS=1hp/MR

Sucess=1hp/MIN

Fail=1hp/hour

Fumble= 1hp/day

Successful treatment will stabilize the wound and stop HP loss.

In the real world, pretty much no one drops dead when they get shot, but everyone dies if they don't treat the wound. Maybe we could apply a modfier to the roll to treat the wound making it harder to stabilize more serious injuries?

BTW, while we are discussing injury. How about we swipe the HEaling Rate rules from Pendragon, where character heal (STR+CON)/10 HP per week? That way healthy character would heal faster than small sickly ones? It always bugged me that the guy with an 18 CON took just as long to heal from a 3 point injury as the guy with a 6 CON.

Chaos stalks my world, but she's a big girl and can take of herself.

Link to comment
Share on other sites

Interesting, but I7d say use POW or CHA to continue acting rather than CON. It really isn't so much a question of your health, but of you determination.

...

BTW, while we are discussing injury. How about we swipe the HEaling Rate rules from Pendragon, where character heal (STR+CON)/10 HP per week? That way healthy character would heal faster than small sickly ones? It always bugged me that the guy with an 18 CON took just as long to heal from a 3 point injury as the guy with a 6 CON.

I like both those suggestions! :)

SGL.

Ef plest master, this mighty fine grub!
b1.gif 116/420. High Priest.

Link to comment
Share on other sites

It would be Self-Discipline to continue, not CON. Some very non-physical people have survived debilitating wounds and continued to act as was needed in the circumstances, only to succumb from those wounds once the crisis was past. It's called shock, and it can take hours to set in, and it can be fatal.

The very existence of flamethrowers proves that some time, somewhere, someone said to themselves, "You know, I want to set those people over there on fire, but I'm just not close enough to get the job done."

George Carlin (1937 - 2008)

_____________

(92/420)

Link to comment
Share on other sites

Atgxtg- I think I wrote poorly for the first example. I was thinking in terms of CON to survive a round to a limb affecting the CNS. Obviously it isn't a great chance but there is research that records shock waves impacting and disrupting or damaging the brain from shots to limbs.

I like some of your ideas but I think that your chart needs to be turned the other way in the interests of PC survivability and just roll vs 5x CON.

CS=1hp/day

SS=1hp/hour

Sucess=1hp/MIN

Fail=1hp/MR

Fumble= 1hp/SR

__________________

Joseph Paul

"Nothing partys like a rental" explains the enduring popularity of prostitution.:eek:

Link to comment
Share on other sites

I think I prefer Damage vs CON on resistance chart rather than straight CONx5%, since a more devatating injury should be more lethal.

BTW, I looked over the CoC 5th eidition damage rules, and I have to argree with Joseph Paul, they are outta whack. First edition damages were better. While the .45 vs 9mm thing is debatable (although it does cause a problem with armor, since anything that will stop a 9mm WILL STOP a .45), but I can't accept that a .44Mag is doing the same damage as a 5.56 round, and only 1 point less that a Browning .30 cal.

IT looks like the CoC tables stressed bullet diameter a bit too much.

I messed around with 3G and the CoC damage scale, and used a nonlinear progression for damage (roughly based on the square root of the rounds ability to penetrate) and came up with:

Round CoC(Revised)

.22 1D6(2D3)

.25 1D6(1D6-)

.32 1D8(1D6)

.38 1D10(1D6+)

.38S -- (1D8)

9mm 1D10(1D8)

.357M 1D8+1D4(2D4)

.45 1D10+2(2D3 or 1D8)

.44M 2D6+2(1D10)

.22LR --(1D6+2)

.30car 2D6+2(1D6+1D4)

.30-06 2D6+4(1D10+2)

Barrett M82 (.50cal) 2D10+4(1D10+1D8)

5.56N 2D8(2D6)

7.62R 2D6+1(1D10+2)

7.62N --(1D10+2)

BTW, If we use that "survival roll" thing I came up with, then we can give the .45 the lower damage roll (2D3), but apply a +3 modifier to it's damage for the survival roll, and for "stun/shock" roll.. This would keep it's stopping power while giving it a lower penetration ability.

Chaos stalks my world, but she's a big girl and can take of herself.

Link to comment
Share on other sites

.45 1D10+2(2D3 or 1D8)

With hit locations gone, won't that make the damage a bit too low? It would on average take 3 normal hits to kill someone with a .45 with those revised damages. Some armor in addition would make it really hard.

(must say, I have not that much experience with firearms and RPG so I do not really know how it works during play)

Sverre.

Ef plest master, this mighty fine grub!
b1.gif 116/420. High Priest.

Link to comment
Share on other sites

Here my opinion about gun damage. The values seem fine but I think that guns should " Impale" and do double damage on any special hit. This is to reflect that a normal shot just hits muscle but a special shot would then hit an artery, vital organ ect.

We used this rule as well, and it worked fine.

BRP Ze 32/420

Link to comment
Share on other sites

Here my opinion about gun damage. The values seem fine but I think that guns should " Impale" and do double damage on any special hit. This is to reflect that a normal shot just hits muscle but a special shot would then hit an artery, vital organ ect.

In the black powder rules we've used locally, we treated regular bullets as impaling damage and shot as crushing damage (in the RQ: AIG sense) and had it vary according to range; double at short, half at long.

Link to comment
Share on other sites

And, FWIW, when Sandy devised the damages for Cthulhu Now, he did use Jane's. IIRC, he based the damage on the amount of pressure at impact.

It seems to make more sense, as listed above, to enforce Impale and Critical hits, along with major wound than to rework the whole list.

SDLeary

Link to comment
Share on other sites

While impact energy isn't a bad metric, its not entirely the whole story, either.

Very true. But for a simple (in terms of combat) game like Cthulhu, it made sense. And it does give a very very good baseline to work from.

By enforcing impailing (I would limit this to first round in a burst, as in the rules), and criticals, you enable almost any round to not only take big hulking types down, but to kill them.

I've been toying with the idea that criticals are auto death in the head and chest, but for NPCs... kindof a toned down mook rule.

Adding special rules for round types, etc., would cover most variation. For example, the 4.6 x 30mm round used in the new MP7 PDW. Its a small and light round (For those of us in the states, the bullet is .177 cal., the same as many air rifles). Because of this the actual standard damage should be low. The round has excellent armor penetration though. On a special, I would allow three rolls of the dice for damage, similar to the way a rapier impales in RQ.

Other options might be impaling for jacketed rounds, and nothing special for unjacketed. Not sure about hollow points and the like though.

The extremely long winded point being that the current tables can be tweaked for better real world performance, and left alone for the light games.

SDLeary

Link to comment
Share on other sites

Some of our house rules for special ammo are

-AP round: 1/2 targets armor

-explosive round (SciFi): +1d6 damage

The above house rule for AP rounds are only applicable if you use fixed armor instead of variable (like in SB). If we use variable armor then then we scale the armor roll 2 dice down. (eg. a 1d10-1 becomes a 1d6-1)

The above AP rule could also be used for warhammers/warpicks, some specialized crossbows and other armor breaking gear.

Link to comment
Share on other sites

Very true. But for a simple (in terms of combat) game like Cthulhu, it made sense. And it does give a very very good baseline to work from.

Its certainly better than muzzle energy which I often find a bit dodgy to use by itself.

By enforcing impailing (I would limit this to first round in a burst, as in the rules), and criticals, you enable almost any round to not only take big hulking types down, but to kill them.

I'd have never thought of _not_ giving firearms impaling damage, to tell the truth. I have to remind myself its not standard to non-RQ versions of BRP.

I've been toying with the idea that criticals are auto death in the head and chest, but for NPCs... kindof a toned down mook rule.

I don't think that'd be necessary, honestly; impales are usually ugly enough to do the job. There are some problems with criticals in some versions of BRP not dealing with unarmored targets well, but I think that needs to be addressed generically; its not just a problem with guns.

Link to comment
Share on other sites

The reduced damage values would work with the bleeding rule I inbtroduced eariler.

As for the damaged in the book, they are pretty random, and do not match up well with the actual energy of the various rounds. FOr example a .38 round is not nearly as lethal as a 9mm round. A .38 special round on the other hand is.

The big problem I have with the 5th edition damage is that the pistols are overpowered compared to the rifles. For example, an 5.56 nato round has more energy than a .44 Mag, yet the damages are about the same. It also has nearly twice the penetrating power, an important factor when dealing with body armor.

First edition CoC (and most Chaoisum products) put the 9mm at 1D8 so I went with that.

I suspposed I could redo the damages with the 9mm at 1D10 and shift up the rifles a little, but was worried about making some weapons "autokills". With general HP and little armor to speak of, I am concerned about making the guns too lethal. In the real world, one shot from most weapons won't kill you-at least not right away. Lying on the ground, bleeding, crying for your Mommy, yeah, but not dead.

BTW, I was assuming that double damage on an impale was still the standard rule for CoC, so that, combined with the shot range modifier would make most pistols pretty dangerous at the 20 foot range that they are typically used at.

Chaos stalks my world, but she's a big girl and can take of herself.

Link to comment
Share on other sites

As to impaling I've always had guns Impale. That is only way a handgun can kill in one shot typically.

To accurately model modern ballistics Penetration (the ability to penetrate armor and other hard substances) and Damage should be differentiated. The Armor absorbing damage model of BRP fails to capture this. It works well enough for Melee weapons, but with modern ballistics, armor piercing rounds, hollow point and hydroshock rounds, and advanced weapons like flechette weapons the combined damage/penetration used by BRP starts breaking down.

A 9mm should penetrate better than a .45, but the .45 should be more effective against an unarmored foe. A shotgun does massive damage against an unarmored foe but is not effective against armor. Flechette is sort of the opposite of the shotgun (high penetration but low damage - the damage compensated for by volume of fire and low recoil - making it easy to put a LOT of rounds on target).

Armor Piercing rounds should penetrate better than standard rounds, but do less damage. They also suffer a loss of accuracy at long ranges.

Hollow Point rounds should do more damage but armor should be more effective against them.

Without introducing a seperate Penetration value (though adding penetration is certainly an option for an advanced set of rules) I think a guidline like the following makes sense:

AP rounds: Reduce the Damage die one step and any damage add by one. Armor value is halved. Optionally additional hit penalties at long ranges. (A .45 acp does 1d8+1)

HP Rounds*: Increase the Damage Die one step but armor is doubled. (A .45 does 1d12+2)

On an Impale damage that penetrates armor is doubled. A crit Impales AND ignores armor.

Thoughts?

Other areas poorly covered by BRP: Auto-fire, Recoil, Psychology of gun combat (performing under fire), and range system (very poor recreation of snipers using RAW).

Help kill a Trollkin here.

Link to comment
Share on other sites

I think there's certainly an argument that guns are going to look odd as long as you don't differentiate penetration and damage, that's not unique to them; there are distinct problems with other types of weapons in this area, too (as far as that goes the psychology of combat thing is more general; people behave erratically under fire, but I don't doubt the same thing is true when rude people are swinging battleaxes at your person).

Link to comment
Share on other sites

Not too shabby Rurik,

About the only thing I'd dispute is that AP rounds loose accuracy over long distance. I don't think that is a property of AP as much as a property of less mass, and thus lower inertia. Main reason I bring that up is because a lot of AP rounds have increased powder for more energy and flatter trajectories. Oh, and the AP anti-tank round typically have the longest range.

BTW, Sandy may have used Jane's to get the weapon damages, but for whatever reason, those numbers were thrown out when they revised the game. First edition CoC damages are different that what is is 5th, and seem to work better IMO.

P.S. Rurik, you sure you haven't read Timelords? Your damage idea is fairly similar to what they do there.

Chaos stalks my world, but she's a big girl and can take of herself.

Link to comment
Share on other sites

Not too shabby Rurik,

About the only thing I'd dispute is that AP rounds loose accuracy over long distance. I don't think that is a property of AP as much as a property of less mass, and thus lower inertia. Main reason I bring that up is because a lot of AP rounds have increased powder for more energy and flatter trajectories. Oh, and the AP anti-tank round typically have the longest range.

BTW, Sandy may have used Jane's to get the weapon damages, but for whatever reason, those numbers were thrown out when they revised the game. First edition CoC damages are different that what is is 5th, and seem to work better IMO.

P.S. Rurik, you sure you haven't read Timelords? Your damage idea is fairly similar to what they do there.

AP Rounds lose accuracy because they are teflon coated. The reason is that AP rounds are made out of harder metals (steel or alloys) than non AP rounds. When first being developed the hard rounds ruined a weapons rifling in short order. The teflon coating helps reduces friction and so the round does less damage to the barrel's rifling, but also does not 'take' to the rifling as well, and less rotational spin is created (which is the whole point of the rifling).

Good old soft lead takes to the rifling very well so actually shoot straighter (and also does verry little damage to the rifling because lead is so much softer than the barrel's steel).

Positive I've never read Timelords. Sounds decent though.

Help kill a Trollkin here.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...