Firearm-rules in BRP

[Simlasa]

Originally Posted by Enpeze

Not in my games. Maybe this is because I dont normally use CoC monster extensively. (rather humans as opponents) Additionally there is not much combat in my CoC games. Players tend to avoid combat because they know it could be very nasty and deadly to them. Its more an investigate the secrets of supernatural, dark mood game.

Our games are similar... the monsters are there, but you ain't gonna run into them casually... Combat is dangerous enough that we usually try something underhanded like dynamiting the old house they're meeting in... rather than go toe to toe in a firefight. When we have had gun battles the results have seemed pretty plausible... IMHO.

[drohem]

An option to consider is open-ended damage for ballistic weapons.

For example, if the weapons damage is 1d6 and a '6' is rolled, then you roll another d6 and add that to the total damage.

This can be an abstraction of the artery being hit, a bone being smashed into pieces, an organ damaged, etc.

[badcat]

I have used that in games with high, inflating hit points successfully. But we were never quite clear on whether a d8 is actually better than a d6 (for instance). Is better die average over the long run or better chance of rolling max on the first roll going to be generating more damage? A question that always gets asked at a Savage Worlds game, for sure. What do you think?

[drohem]

Originally Posted by badcat

I have used that in games with high, inflating hit points successfully. But we were never quite clear on whether a d8 is actually better than a d6 (for instance). Is better die average over the long run or better chance of rolling max on the first roll going to be generating more damage? A question that always gets asked at a Savage Worlds game, for sure. What do you think?

Here is how a single die looks:

d4 = 0.25 = 25%
d6 = 0.16667 = 16.66%
d8 = 0.125 = 12.5%
d10 = 0.1 = 10%
d12 = 0.08333 = 8.33%
d20 = 0.05 = 5%

So on a d6, you have a 16.66% chance to roll a '6' and a 83.33% chance not to hit a 6. So each number on a d6 has a 16.66% chance to come up.

So on a d8, you have a 12.5% to roll a '8' and a 87.5% chance not to hit a 8. So each number on a d8 has a 12.5% chance to come up.

This changes of course when you roll two dice together (i.e. 2d6). Then you have a greater or lesser chance to roll a specific number within that range.

2d6
2 - 2.78%
3 - 5.56%
4 - 8.33%
5 - 11.11%
6 - 13.89%
7 - 16.67%
8 - 13.89%
9 - 11.11%
10 - 8.33%
11 - 5.56%
12 - 2.78%

So hitting a 7 has the greatest chance at 16.67% while hitting a 2 or 12 has the least chance at 2.78%.

Here is a link to a cool dice probability calculator you can play with:
http://www.anwu.org/games/dice_calc.html

Here is another probability links you might find useful:
http://www.edcollins.com/backgammon/diceprob.htm

[badcat]

Yes, I understand the percentages, but which die do you think will yield the highest damage in the long run? A d12 has the highest immediate results and the d4 explodes more often, so would you take a d6 shortsword or a d10 bastard sword?

[drohem]

Originally Posted by badcat

Yes, I understand the percentages, but which die do you think will yield the highest damage in the long run? A d12 has the highest immediate results and the d4 explodes more often, so would you take a d6 shortsword or a d10 bastard sword?

In my gaming experiences thus far using the open-ended damage for ballistic weapons and falling damage, I would have to say the d6 yields the greatest damage. Even though a d4 looks like it would because of the chance, it has appeared to me that the d6 is the most solid for re-rolls.

[Enpeze]

Originally Posted by Atgxtg

Not all version of BRP have this sort of rule. Stormbringer7s Major Wound might be the best. But, even with such a rule, in many cases the way damage works means than some weapons are not going to be able to do half someone's HP.

You mean the lighter fire weapons? Maybe they dont deal half HP always but in reality those weapons lack stopping power too, no?

Originally Posted by Atgxtg

Maybe , but that sort of makes you CoC campaigns an exception. Most CoC games I've played in and all the published adventures I've read use the Mythos monsters. I did enjoy one exception when a local GM ran an adventres based around gansters that threw us for a loop. We were expecting Mi-Go and ended up facing bootleggers with Tommy Guns.

Well you are right. My players learned it the hard way to stay away from frightening things. (tommy guns included) Play the rules as they are, dont fudge dice is my motto.

Originally Posted by Atgxtg

One way to go. BTW, does that work against PCs or is there some sort of save/resistance?

I dont differentiate between PCs and NPCs. Every entity gets a POWx1 luck roll as "intuition-save" shortly prior to the assassination attempt. If it succeeds, the assassination becomes just a normal attack. There are one or two additional rules too, but this would lead too far.

Originally Posted by Atgxtg

Not really. Any game with Cthulhu, Deep Ones, etc isn't realistic. The underlying BRP mechanics are more realistic than d20, but it really don't play much of a factor for that sort of setting.

In this I fear we have to disagree. Maybe we have different conceptions was realism is?

Originally Posted by Atgxtg

Name a realistic RPG that doesn't have some degree of rle complexity.
Please don't imply that GURPS is my game of choice, it isn't. IMO GURPS does more things wrong than it does right (1pt knife damage, the inability to defend youself with a weapon without a superhigh skill or armor). I7d take Timelords, CORPS, HARNMASTER or a bunch of other before GURPS.

Well I didnt play one of these games. I read Corps and harnmaster. So I had not the impression that one of it is much more realistic than BRP. Maybe harnmaster is on par with BRP but at the expense of more complex rules and a higher learning curve, but corps?

Originally Posted by Atgxtg

Because I've yet to see published CoC products that promote any other sort of adventure. Yes, you can take CoC throw out all the mythos stuff, and use it for something else, but that isn't what's been published. Admittedly CoC is my least favorite Chaosium RPG.

Well if I play official modules then only those from Pegasus Press in Germany. And these are absolutely great. There are some with emphasis on combat too, but often they are offering multiple path to success and you can often solve the thing without much combat.

Using the BRP system of CoC (modified) for other settings is not a big deal for me. I do it the whole time. Its simple. Everyone in our group knows the rules (at least they pretend ). We love the intuition behind rolling everything with d100, the grittyness of the system, and we all dont like traditional level based systems or dice pools at all. So BRP serves our needs perfectly.

Originally Posted by Atgxtg

Again it depends one what sort of campaign. I think I prefer a "medium" caqtegory just to dintinquish between the typical pistol that most people, law enforcement, etc carry and a hold-out gun like a derrigner.

But in some games and gneres, it can be important and worth differntiaing. For CoC Light/heavy is fine. For, say a James Bond style episonage game, a modern warfare game, or a Old West campaign, a bit more detail really helps.

Many years ago I played a JB game. It was not my liking (too cinematic). For modern warfare you may be right.

[Enpeze]

Originally Posted by Simlasa

Our games are similar... the monsters are there, but you ain't gonna run into them casually... Combat is dangerous enough that we usually try something underhanded like dynamiting the old house they're meeting in... rather than go toe to toe in a firefight. When we have had gun battles the results have seemed pretty plausible... IMHO.

Yep. Most CoC players I know and deal with have the same indirect style. If you play action and combat oriented your PCs end will come soon. (maybe in the first session)

[Joseph Paul]

Enpeze wrote:

You mean the lighter fire weapons? Maybe they dont deal half HP always but in reality those weapons lack stopping power too, no?

Well no that is not true actually and that is one of the rubs. "Stopping power" is a misnomer and leads us to think that more energy will always drop some one faster. The correlation is more complex than that. Understanding it is not helped by some of the material that is out there nor by the stances that some of the authors take.

Here is a link to a paper that expresses the views of Martin Fackler who works in the Wound Ballistics Lab of the US Army. It is about what he thinks is wrong with the literature on the subject in 1987. http://teapot.usask.ca/cdn-firearms/Fackler/wrong.html

Here are excerpts from Dr. Vincent di Maio's book "Gunshot Wounds" that expresses other views on what happens. http://karws.gso.uri.edu/JFK/scienti...igh-speed.html

Here is a critique of objections to the pressure wave data. http://arxiv.org/ftp/physics/papers/0701/0701268.pdf

It is agreed that there are reports, pro and con, for just about any cartridge. The problem is the huge variability in conditions under which shootings takes place.

Out of the long debates on such things there have come some very rough rules of thumb.

1. Location is very important. If you don't affect arteries, organs, or the nervous system you will fail to physically incapacitate your target. This is seen in hunting scenarios all of the time. Two bucks are shot under very similar circumstances; one drops immediately and the other bounds away to bleed out later -or not.
2. The round needs to be able to penetrate the body an appropriate distance to increase the likelyhood of striking blood vessels, organs, or the CNS.
3. Temporary cavitation may or may not have any serious effect on stopping a target. fragmenting rounds help with this by perforating tissues that then tear. In hand gun loads this does not seem to be a concern. In high velocity rifles it is.
4. The permanent wound channel may be the only mechanism for damaging a target. It is caused by the round crushing tissue. It will be the size of the round plus expansion of the bullet or slightly larger for non expanding bullets that have flipped end for end in the target.
5. Damage to the CNS via a pressure wave is controversial but seems to be gaining support.

Given these guidelines it appears to me that most games are treating the resolution of firearms wounds in a very unrealistic manner. BRP rewards the use of more powerful handguns, ups the damage from smaller calibers to make them competitive in the HP-damage model, and does not model any of the other effects of gunshot wounds. It does not reward superior shot placement nor is the random shot given any bonus or minus for striking various parts of the anatomy. Some have advocated the rules for specials and criticals as modeling this. However the 20/5 % Special/crit rules are applied in a rigid fashion with no concern for RW data on actual frequency of incapacitation by particular calibers/loads/bullet types.

As an "easy" house rule it may be possible to assign different special/crit percentages to various firearms. This could even be broken out as a 'smorgasbord' table where players pick the gun, the load, and the bullet type to suit their (percieved) needs. Each element would be rated for effectiveness and each would be additive with the others to arrive at a % chance for at least 'special' damage. This damage need not be extra points of damage but could instead be used to force a resistance roll on the target to remain concious etc.

Regular damage i.e. 1d6+1 etc would then represent having to pick at the target and hope that you can reduce him to 2 HP (is that what it is in BRPCore now?) before he kills you.


Further, my initial concern was that retaining firearms damage ratings that are not based on RW parameters makes it harder to do some things like create technological design sequences for BRP.

I am in favor of adjusting damage of firearms so that it scales in a predictable manner and is tied to real world data.

Once that baseline is set then working out the wounding mechanics to fit various levels of play (gritty, heroic, cinematic etc) should be fairly easy. I am confident that it can result in more realistic results with little to no sacrifice in playability.

[Rurik]

Originally Posted by Joseph Paul

I am in favor of adjusting damage of firearms so that it scales in a predictable manner and is tied to real world data.

The question becomes which real world data do you use? It seems people can never agree on that.