Saturday, June 5, 2010

"Gun in a Knife Fight" (Gun damage mehcanics)

"Why is it SO HARD to design solid gun damage mechanics in a traditional RPG game?"

I asked myself this while I was pondering the effectiveness of a gun my character invented in a friend's Pathfinder game. In my mind a bullet means you die or at least are incapacitated. I'm dealing d10s with it and it reloads like crossbow (mechanics wise) thanks to some design improvement and creative GMing. It got me thinking- can guns effectively be balanced into a RPG setting? (Fantasy or otherwise)

First I decided that I needed to find out just how many wounds a man can take before they go down. Figuring that out I'd do some funky math to see if I could average out HPs for characters across the board, then divide it by the number of wounds a man could take (on average) before they went down. I'd try to find a dice size that reflected the average damage and go from there. Sounded good in theory. (At least to ball-park the damage size)

I did some research and in the end came up with a very interesting finding from the FBI Firearms Training Unit.

Conclusions from Handgun Wounding Factors and Effectiveness, a Department of Justice report by the FBI Firearms Training Unit


Physiologically, no caliber or bullet is certain to incapacitate any individual unless the brain is hit. Psychologically, some individuals can be incapacitated by minor or small caliber wounds. Those individuals who are stimulated by fear, adrenaline, drugs, alcohol, and/or sheer will and survival determination may not be incapacitated even if mortally wounded.

The will to survive and to fight despite horrific damage to the body is commonplace on the battlefield, and on the street. Barring a hit to the brain, the only way to force incapacitation is to cause sufficient blood loss that the subject can no longer function, and that takes time. Even if the heart is instantly destroyed, there is sufficient oxygen in the brain to support full and complete voluntary action for 10-15 seconds.

Kinetic energy does not wound. Temporary cavity does not wound. The much discussed "shock" of bullet impact is a fable and "knock down" power is a myth. The critical element is penetration. The bullet must pass through the large, blood bearing organs and be of sufficient diameter to promote rapid bleeding. Penetration less than 12 inches is too little, and, in the words of two of the participants in the 1987 Wound Ballistics Workshop, "too little penetration will get you killed." Given desirable and reliable penetration, the only way to increase bullet effectiveness is to increase the severity of the wound by increasing the size of hole made by the bullet. Any bullet which will not penetrate through vital organs from less than optimal angles is not acceptable. Of those that will penetrate, the edge is always with the bigger bullet.

(Note: I also read quite a bit from a thread on a forum called "The Firing Line" ( among other sources. This was a very interesting thread and contained the above snip-it)

So... how can we reflect this in a game? I like working with the d20 mechanics and most of us are familiar with them (those who have read this blog for a while know I love me d100s though... or reading of animal entrails...)

Based on what I can find dexterity should play a roll and the weapon should have a very high crit. (x3?) but low crit range. (19-20 should do it). Ammo should be a very big factor (especially in modern settings). A standard shot from a .22 can drop a man just like a well placed blow can devastate someone. One of the factors they keep going back to however is internal damage (especially when talking about hollow points).

I'm not 100% on how to do this but I do find it interesting. It's like trying to balance a gun in a knife fight- the "great equalizer" it's intentionally easy to use (point, click, BOOM) and deadly even in the hands of an amateur (though more so in the hands of an expert). If you've got any ideas yourself- please post them up in the comment's section!

If we are looking at old-school guns (like muskets) they where notoriously hard to aim (until the advent of rifling) and the took a while to re-load. One way to do it is to employ a high/low scenario with guns. VERY high damage but VERY long reload time.

"A skilled unit of musketeers was able to fire three rounds per minute when drilled. An experienced individual could manage four rounds a minute if firing at will, such as in a skirmish situation" (That came from Wikipedia but I've heard similar figures elsewhere)

That means that if we divide the 60 second in a min by the 5 shots per min we get 12 seconds. If I recall correctly, in pathfinder a turn represents about 6 in-game seconds. Two move actions would be quite the reload time. A normal reload time is 1 move action for a hand or light crossbow or a full-round action for a heavy crossbow. (With the "rapid reload feat" they can be a free and a move respectively) Two standard actions to load (1 with Rapid Reload) would be a LONG time but if the damage was high enough it might be viable. The damage would have to be twice that of a heavy crossbow as a result and we can a little for the risk.

Crosbow, Heavy

Cost: 1gp

Damage (Small): 1d8

Damage (Medium): 1d10

Crit: 19-20/x2

Range: 120

Weight: 8lbs.

Type: Penetrating

Special: --


Cost: 10gp* (Up to GM)

Damage (Small): 2d8

Damage (Medium): 2d10

Crit: 19-20/x3

Range: 120

Weight: 10lbs.

Type: Penetrating

Special: --

Notes: Takes 2 standard actions to reload. (1 with rapid reload)

1d10 becomes 2d10 for the double reload and the x2 becomes an x3 for the risk. It is meant to represent a headshot or other critical area (hit to the heart, ect)

Now modern guns are also something that we should conciser. Can a M16 REALLY not kill someone with a nice tight grouping? Comment and lets talk about it! :D


  1. Also:

  2. I read your blog post, and I love the idea of incorporating that "will to live" somehow. Personally, I would try to develop a "resilience" mechanic of sorts to help balance this.

    For example, let's say John has a knife and Jacob has a gun. Jacob probably has a higher chance to land a critical hit, making it easier for him to reduce John's HP to zero. However, let's say John has Resilience - a passive ability that has a chance to trigger when John takes a critical hit. It lasts for...let's say 3 turns for example. While under the effects of Resilience, John gets a bonus to critical hits - depending on a roll - and each time he successfully hits Jacob, he temporarily regains an amount of health equal to 25% of the damage he deals. After the 3rd turn, when Resilience ends, John loses all but 1 HP (or perhaps just loses all of the bonus health gained during Resilience).

    I'm not 100% sure how well this would work, but this is definitely the direction I would go in. I hope that helps spark some ideas! :)

  3. Personally I say it depends of what's more important to your gameplay. Realism or metaphysics?

    If metaphysics - I'd say pull an Indiana Jones- in Raiders their is a single awesome prep to fight sequence (the guy with the sword) and then Indy pulls the Mauser and the fights over in half a second. But in other instances like Temple of Doom, His gun can get lost or runs out of bullets or the camera pulls to the actors side and three minions are able to attempt disarm.
    GM's have a strong built in mechanic to RP's and that's story telling. As Stan Lee commented about who could win vs. who or what - It only depends on the writer, and nothing else, you can have a kid kill Superman. Balance doesn't really need to matter in the end it's the DM's job to shape a great story with the help of the players and the rules be dammed.

    For a sense of realism - the Mechanic you might want to consider the dramatic effects of the weapon. And then compare it with your world's realism. Do your players expect to be able to murder anyone they feel like? Do they cut NPC's down like a hot knife threw butter? Do massive blows send people flying threw doors and windows only to get back up and do it over and over again until HP has been dropped? Do you like telling your PC's 'Hey that crit caused you to do something supernatural?'Or is it gritty? do your players have to spend time to be careful of a scratch from a rusty, fetid, gore covered, sword for fear of disease?

  4. I mean it looks like you've gotten your sources together as to how guns can effect people , but As a number crunch - guns are perfect. Think about the best range weapon/spell in any RPG- and a gun can be that. What I mean is that unlike many conventional spells or weapons they can cover a wide range of use and function, close- far- single target, multiple target, modern day guns in a D20 environment are perfect. And often they are extremely overpowered in a RPG setting, so you can either Nerf them, by removing accuracy- (Stormtrooper Bootcamp) Or their ability to do damage which makes them closer in line to the crossbow and longbow.
    But inusing today's standard really a standard effect unless you get into the realm of the very high tech (1947 and later.)

    Maybe a 2-3 round reload on blackpower weapons is needed in certain cases- but also the damage may not need to be about Hp but location? Think about if players played 'Die Hard' as a RPG. How messed up can a player be from cutting up his/her feet? How much HP does that take? Are your players like John McClain and need to take care of their feet and have consequences for not doing so? Is it a minor thing for the players to overcome? Or would it effect certain things like movement speed, carrying capacity or how many movement actions they could take in a round?

    These are all things which could be worked out-

    but back to the gun vs. knife. In a straight up fight of one person with a musket and another at the end of a hall with a knife the musket will wing with such a higher percent of victory that realism would not make it fun for both sides. But then the question says let's remove distance. I'm not certain as to who would win in this set but I would believe that some of the kills would still go the the musket user. I believe that you can't make the fight fair you're describing without breaking into the metaphysical, which again gives a strong case to stoytelling..

    Keep the weapon basics as they are- range and initial damage. But maybe expanding the criticals system you might be able to make a knife just as deadly as a gun.

    What I purpose instead develop a critical trauma table that effects stats or other types of penalties like poison or disease does in 3.0 and 3.5. Extensively this could make every weapon lethal at all levels knife, gun, axe, lightsaber, what have you. This could also add a higher sense of realism, especially with weapons that can deal massive one hit kills. Or even very skilled assassinations. What this also means is that the need for bonus weapon damage would not be needed or could be implimented threw ammo types or greater bonuses to the trauma tables, like hollow points or massive burning or the like.

    This type of table to give players abilities to forgo effects like backstab damage bonus but instead effect the player to bleed- loose HP over turns with certain actions causing further loss or loss at increased rates, ruptured organs - drop in Con, rip out tendons- losses to Dex, broken bones etc. etc. Allow rouges and other trained classes/ feats to use the called shot action with greater effect. And could be greatly used for ninja kills- ei neck snapping, and long range head shots.

    This would be a massive undertaking but if tabled right and if worked out with a mortician/doctor this could make any RPG awesome to be apart of.

  5. @Nick
    I am not re-designing the D20 system in this case but if I did- the shock and awe system used in some games would work. There are system that have things called condition tracks that you move down. A condition track allows your body to take a beating but keep on going if you are bad ass but fatal injures still slow you down.

    I love it!
    I've seen some system (Dark Heresy) for example that uses different areas of damage. It wouldn't have to be a complex system. Speaking in D20 terms it could be a roll after you hit to see where your blow lands. Having done some old-school live combat (not “live action”, LIVE combat) I can tell you it's VERY hard to hit a guy with a shield in the chest and the head is guarded pretty jealously. Called shot might lower your “to hit” roll but allow you to select where the hit lands. It might looks something like this:
    1-3 Lower Body
    4-6 Arms
    9-12 Chest (Shield negates. Does not provide AC bonus)
    13-16 Back
    17-19 Head
    20 Vital Area

    Sneak attack could be re-worked (because D20 systems don't employ facing) to always score on vital or get a plus to roll on the chart. (Though then Rogues don't EVER hit feat or arms... XD )