D&D 5E Why do guns do so much damage?

[jhingelshod]

Doing some quick calculations...

There were 34 pistol balls to the pound for English Pistols. That means each one is about 0.029lbs or about 0.013kg.

The muzzle velocity of a musket is the closest approximation we have of acceleration... so let's just input that value whole instead of acceleration at 414m/s.

And that gives us... 5.9 Newtons of Force. That's pretty great!

Average weight of a Longsword was between 1 and 1.5kgs. Averaging it out, let's go for 1.25kgs. Let's compare them to Baseball Bats for ease of "Fast Speeds". The fastest swings of a bat are around 41mph or 21.4m/s. Let's put that in annnnd....

26.75 Newtons of Force.

Even with it's -vastly- lower speed (just over 1/20th!) the longsword imparts nearly five times as much force as the bullet does. Even dropping the sword's swing speed to 12.1m/s (about 20mph, the "Slower" swings of a bat) you wind up with 15 Newtons of Force which is still three times as much.

While I had a gut instinct that a heavier weight would impart more force just through simple mass, I didn't expect the force difference to be -this- drastic.

... That's -interesting-...

And also very wrong.

Force is mass x acceleration, not mass x velocity.

Force as you describe it, is not a useful metric when discussing damage. When I sit in my chair, my 75kg mass accelerating at 9.8ms^-2 under the effect of gravity puts a force of about 750N through my butt...

What causes damage is impulse* (change in momentum) over very short times causing huge forces to occur and catastrophic amounts of energy to be released over a short time, which is why cars are designed with crumple zones, and why climbing ropes are stretchy.

Lets say I run into a brick wall at 5ms^-1. It's pretty hard so I come to a halt in 0.05 seconds.
Before I hit the wall, my momentum is m x v = 75 x 5 = 375Ns. Afterwards is 0, so the impulse is 375Ns (meaning that 375N of force would be required to stop me in 1 second). Unfortunately for my teeth, I come to a halt in 0.05s meaning that I experience 375/0.05 = 7500N for 1/20 of a second, 10 times what my body normally experiences. This is what motor-racing commentators call a 10G impact.
Now put some padding on that wall. I still come to a halt, but now it takes 0.25s. Same change in momentum but now dividing by 0.25 gives a smaller force of 1500N...a 2G impact.

*yes, I know I'm ignoring things like pressure, cutting, penetration etc

 

[Steampunkette]

And also very wrong.

Force is mass x acceleration, not mass x velocity.

Force as you describe it, is not a useful metric when discussing damage. When I sit in my chair, my 75kg mass accelerating at 9.8ms^-2 under the effect of gravity puts a force of about 750N through my butt...

What causes damage is impulse* (change in momentum) over very short times causing huge forces to occur and catastrophic amounts of energy to be released over a short time, which is why cars are designed with crumple zones, and why climbing ropes are stretchy.

Lets say I run into a brick wall at 5ms^-1. It's pretty hard so I come to a halt in 0.05 seconds.
Before I hit the wall, my momentum is m x v = 75 x 5 = 375Ns. Afterwards is 0, so the impulse is 375Ns (meaning that 375N of force would be required to stop me in 1 second). Unfortunately for my teeth, I come to a halt in 0.05s meaning that I experience 375/0.05 = 7500N for 1/20 of a second, 10 times what my body normally experiences. This is what motor-racing commentators call a 10G impact.
Now put some padding on that wall. I still come to a halt, but now it takes 0.25s. Same change in momentum but now dividing by 0.25 gives a smaller force of 1500N...a 2G impact.

*yes, I know I'm ignoring things like pressure, cutting, penetration etc

And, like most of the other people posting in this thread almost 8 months after it died out, you're ignoring things like... further posts which correct that math.

The point is, and always have been: A sword makes a much bigger hole in the human than a renaissance era pistol ball.

Then insert three or four weeks of people harping on fluid shocks, bullet expansion, velocities, modern deaths by sword and gun attack comparisons, and the occasional "Don't bother discussing it or being curious, it's not simulationist, you fool!"

As nauseum.

I hate thread necromancy so much.

 

[Cadence]

And also very wrong.

Force is mass x acceleration, not mass x velocity.

Force as you describe it, is not a useful metric when discussing damage. When I sit in my chair, my 75kg mass accelerating at 9.8ms^-2 under the effect of gravity puts a force of about 750N through my butt...

What causes damage is impulse* (change in momentum) over very short times causing huge forces to occur and catastrophic amounts of energy to be released over a short time, which is why cars are designed with crumple zones, and why climbing ropes are stretchy.

Lets say I run into a brick wall at 5ms^-1. It's pretty hard so I come to a halt in 0.05 seconds.
Before I hit the wall, my momentum is m x v = 75 x 5 = 375Ns. Afterwards is 0, so the impulse is 375Ns (meaning that 375N of force would be required to stop me in 1 second). Unfortunately for my teeth, I come to a halt in 0.05s meaning that I experience 375/0.05 = 7500N for 1/20 of a second, 10 times what my body normally experiences. This is what motor-racing commentators call a 10G impact.
Now put some padding on that wall. I still come to a halt, but now it takes 0.25s. Same change in momentum but now dividing by 0.25 gives a smaller force of 1500N...a 2G impact.

*yes, I know I'm ignoring things like pressure, cutting, penetration etc

Impulse's Ns is the same units as momentums kg m/s , right?

 

[CleverNickName]

Yeah, if it's truly "reskinned" (same cost, same weight, same range, same drawbacks) then the damage should also be the same.

I'd probably leave it up to the player to tell me how much the musket costs and weighs, and to tell me how loud it is, and how quickly it reloads, etc., using the heavy crossbow as a guide. I'd suggest they keep it pretty close, and step in if things start getting out of hand, but for the most part? I'd let them describe their "weird crossbow" however they like.

I don't see it being a problem unless the player starts insisting their crossbow should do double damage because weighs or costs twice as much as the PHB version. At that point, we are designing a new category of weapon, and I won't go there.

This is all purely academic. I've mentioned this all to my players on a handful of occasions, and so far I haven't had any takers.

 

[jmartkdr2]

Glave Guisarme Volge? Though I always prefered the Bohemian Ear Spoon.

A glaive-guisarme?

A guisarme-glaive?

A glaive-glaive-glaive-guisarme-glaive?

 

[UngainlyTitan]

The thing about firearms, is that discussion about energy delivered by a slug or its velocity kind of misses the point. The effective engagement ranges and rate of fire of modern weapons makes a lot of D&D style combat irrelevant.
It becomes more tactical, impost status effects like pinning, suppressive fire and morale considerations. Most of the time for the modern equivalent of a D&D party would be to break contact a call for backup.

 

[Bill Zebub]

A sword makes a much bigger hole in the human than a renaissance era pistol ball.

Why assume it’s renaissance era? Or that it’s charcoal/sulfur/potassium nitrate propellant? Renaissance craftsmen didn’t have magic, (functioning) alchemy, or imaginary alloys at their disposal.

Look, if you don’t like firearms then give them undesirable stats. If you like them, give them good stats. All these arguments about physics, and what makes a bigger hole, seem to be missing the point of the game.

 

[Cadence]

Why assume it’s renaissance era? Or that it’s charcoal/sulfur/potassium nitrate propellant? Renaissance craftsmen didn’t have magic, (functioning) alchemy, or imaginary alloys at their disposal.

Look, if you don’t like firearms then give them undesirable stats. If you like them, give them good stats. All these arguments about physics, and what makes a bigger hole, seem to be missing the point of the game.

Magic gun inspiration -> An Excerpt from “The Effigy Engine” | Lynch Industries
(full thing is apparently $1.99 for the kindle on Amazon)

 

[Steampunkette]

Why assume it’s renaissance era? Or that it’s charcoal/sulfur/potassium nitrate propellant? Renaissance craftsmen didn’t have magic, (functioning) alchemy, or imaginary alloys at their disposal.

Because that's what the book shows?

Why do you assume it's a regular longsword? Renaissance Craftsmen didn't have magic, functioning alchemy, or imaginary alloys at their disposal! Maybe a "Longsword" is 9ft long, 3 inches thick at it's widest point, and only weighs 3 pounds because of magic!

Like. Seriously. This is not a good faith argument.

Look, if you don’t like firearms then give them undesirable stats. If you like them, give them good stats. All these arguments about physics, and what makes a bigger hole, seem to be missing the point of the game.

And there's the "It's not a simulation" derailment and dismissal. Thanks.

 

[Bill Zebub]

Because that's what the book shows?

Why do you assume it's a regular longsword? Renaissance Craftsmen didn't have magic, functioning alchemy, or imaginary alloys at their disposal! Maybe a "Longsword" is 9ft long, 3 inches thick at it's widest point, and only weighs 3 pounds because of magic!

Like. Seriously. This is not a good faith argument.

Did you perchance mean "weak" or maybe "easily countered" argument? Because the hole you seem to believe you have identified would be in regard to the persuasiveness of my argument, not in my sincerity in presenting it.

In any event, I disagree: swords have basically not improved (much) in centuries, whereas firearms have progressed immensely. So if we take the magic of the D&D world as a replacement for technological advancement, the firearms would be vastly better than the earliest real-world analogues, whereas swords would still be...swords.

And there's the "It's not a simulation" derailment and dismissal. Thanks.

Sorry you feel that way about it. I think it's the most important question in this debate.