Mithril weaponry

[Freespacer]

The DMG states that crafting a mithril longsword only makes it as twice as light and NOTHING more! It especially states that it doesn't make it any easier to wield. Why is that?

I suppose that making a longsword less heavy should impare its ability to do physical damage, but certainly make it a light weapon due to a weight loss.
This technically turns a Longsword into a Shortsword stat-wise.

For long time I was bitching about making a longsword a finessable weapon.
All that really bothers me is the waepon's appearance. Can I call a shortsword as a "light longsword" in terms of weapon lenght? If I can, then I'll possibly change my preferences to shortswords.

[Ernir]

The DMG states that crafting a mithril longsword only makes it as twice as light and NOTHING more! It especially states that it doesn't make it any easier to wield. Why is that?
Because the designers, at that point, apparently couldn't figure out any worthwhile benefit of making the weapon weigh less.

You may want to check out Feycraft weapons in Dungeon Master's Guide 2. They are what Mithral weapons probably should have been to begin with.

Can I call a shortsword as a "light longsword" in terms of weapon lenght? If I can, then I'll possibly change my preferences to shortswords.
You can call your weapon whatever you want. It's called "refluffing", and is very useful for getting your character to "feel" right.

[Killer Angel]

I suppose that making a longsword less heavy should impare its ability to do physical damage, but certainly make it a light weapon due to a weight loss.


The lenght of the sword remains the same. When you're in grapple, a mithril longsword is not the same as a light weapon.

[Pilo]

Compare (IRL) a 1x2meters plate of wood and a plate of lead.

The plate of wood is lighter than the one in lead but the emcombrance stay the same. Not considering the lifting/carrying part, it is not easier to move with one or the other.

[Ryulin18]

You may want to check out Feycraft weapons in Dungeon Master's Guide 2. They are what Mithral weapons probably should have been to begin with.

Complete agreement.

A Mithril weapon is going to be light enough to use without much encumbrance but the weight dealt the damage on a swing.

Feycraft weapons (http://www.imarvintpa.com/dndlive/items.php?ID=3133), just in case you don't have the book. :smallsmile:

[Dusk Eclipse]

Personally I would houserule that mithril weapon count as silver for bypassing Damage Reduction; but that is just me.

[Namfuak]

Well, if we are interested in realism...

A lighter weapon is usually not actually a more effective weapon. By having a weapon weigh more, more force is behind each strike (since force=mass*acceleration, less mass=less force). So, a mithril weapon should actually not do as much damage as a steel weapon. Nowhere in the description of mithril (at least in SRD) does it say that a weapon made of mithril is sharper than one of steel, so in this case steel is actually a better material component than mithril. If you wanted to have a mithril longsword, having a mithril shortsword and calling it a longsword would probably be as close as you will get.

[Deepbluediver]

A lot of the upgrades for weapons and armor under the RAW are not very good. There are a couple other minor benefits to having a mithral weapon, such as increased hardness and HP, but yeah it seems they didn't do a lot of thinking on this point. There are quite a few fixes for weapons and armor in the homebrew section.

[Snowbluff]

Well, if we are interested in realism...

A lighter weapon is usually not actually a more effective weapon. By having a weapon weigh more, more force is behind each strike (since force=mass*acceleration, less mass=less force). So, a mithril weapon should actually not do as much damage as a steel weapon. Nowhere in the description of mithril (at least in SRD) does it say that a weapon made of mithril is sharper than one of steel, so in this case steel is actually a better material component than mithril. If you wanted to have a mithril longsword, having a mithril shortsword and calling it a longsword would probably be as close as you will get.

Well... You're wrong. You are suggesting that the mass of the weapon causes force... that's really wrong. F is constant (You are swing with an ARM, which gives force), and when using a lighter weapon that weighs half as much you get DOUBLE the acceleration. You would be losing force due to gravity, but that would only affect Top to Bottom swings, and you'd gain more net force on Bootom to Top swings.

A light weapon would be able to move a lot more quickly, like that of a Light Weapon. I'd house that 1h Mithril Weapons count as Light for things like TWF.

[Nerd-o-rama]

No, the mass of the weapon still matters. A heavier weapon is going to have more energy, momentum, or force (however you want to phrase it) while moving at the same velocity (and getting/giving the same delta-V when it hits something). This is why it hurts more when you hit someone with a solid steel bar as opposed to, say, a whiffle ball bat, assuming you can swing the former at any appreciable velocity (it does obviously take more force from your arm to accelerate a heavier weapon in the first place). Force is not a constant when we're talking about the mechanics of swinging a weapon. Now, when you hit someone, the force with which you hit them is going to be equal to the opposing normal force from their flesh/bones/armor, but that's an entirely different story.

As for the game question, there really is no particular reason to make a weapon out of mithral unless it is very heavy and you have low strength. If not, make it out of adamantine or something instead. Weapon size is about size, not weight.

Alternatively, use a shortsword and call it a mithral longsword.

[Snowbluff]

No, the mass of the weapon still matters. A heavier weapon is going to have more energy, momentum, or force (however you want to phrase it) while moving at the same velocity (and getting/giving the same delta-V when it hits something). This is why it hurts more when you hit someone with a solid steel bar as opposed to, say, a whiffle ball bat, assuming you can swing the former at any appreciable velocity (it does obviously take more force from your arm to accelerate a heavier weapon in the first place). Force is not a constant when we're talking about the mechanics of swinging a weapon. Now, when you hit someone, the force with which you hit them is going to be equal to the opposing normal force from their flesh/bones/armor, but that's an entirely different story.

Good point, but a wiffle bat hurts less to the material, not necessarily the weight.

I would the the determining factor would be how quickly you can actually move your arm, since you would be getting diminishing returns on lower weapon weights due to this. Keep in mind how you move a longsword or shortsword is different compared to you would swing a great sword or kilij.

[Spiryt]

Sword out of less dense metal is not desirable at all, neither is very light sword, and actual swing characteristics aren't even most important here.

No matter how fast someone can move his arm around, sword with lower sectional density at the point of impact won't cut as well, lighter sword will be also stopped way more easily, will be prone to shock, vibration etc. that arm/body of the wielder can really damp only in limited way.

Mithril longsword cannot be considered 'shortsword' because it's obviously... longer. :smalltongue:

So all in all, mithril weapons indeed don't make much sense, and thinking too much about them can only bring headache. :smallwink:

[jmelesky]

Personally I would houserule that mithril weapon count as silver for bypassing Damage Reduction; but that is just me.

That was either common enough or sensical enough for Pathfinder to do the same (http://www.d20pfsrd.com/equipment---final/special-materials#TOC-Mithral).

[Laniius]

Personally I would houserule that mithril weapon count as silver for bypassing Damage Reduction; but that is just me.

Already does in pathfinder.

[jaybird]

Okay, mechanics time.

Your arm generates a force F that is constant.

Force is the product of mass and acceleration, so if mass is lower, acceleration is greater. Specifically, as mithril halves weight, acceleration doubles for the same force.

Work is the product of force F and distance D. Because force is constant and distance is constant (arc of the swing), we're doing the same amount of work with a lighter sword as we are with a heavier sword, assuming we use the same force.

When work is done upon an object causing it to move (assuming 100% efficiency), work equals the change in kinetic energy. Therefore, we are now at:

W=KE

Because work equals force times distance:

F*D=KE

Substituting in the kinetic energy equation:

F*D=(0.5)m*(v^2)

Breaking down F into components m and a:

m*a*D=(0.5)m*(v^2)

Dividing by m:

a*D=0.5(v^2)

Moving a to the other side of the equation:

D=0.5(v^2)/a

Still with me? Recall how, because we halved mass while holding force constant, acceleration doubled over the same distance? Now, if we let a equal the acceleration of a steel sword, 2a equals the acceleration of a mithril sword. Because distance D of the swing is constant, we can say:

0.5(vs^2)/a=0.5(vm^2)/2a

Where vs is speed of the steel sword and vm is speed of the mithril sword. Simplifying:

vs^2=(vm^2)/4

Taking the square root of both sides:

vs=vm/2

We have concluded that the mithril sword is twice as fast as the steel sword for half the mass.

Here's where we start getting a little fuzzy. From what I remember of paintball physics, it's impulse (the change in momentum) that determines the girly screaming quotient :smallbiggrin:

Impulse equals the product of mass and velocity. The steel sword is TWICE as heavy as the mithril sword, but HALF as fast. Therefore, the two weapons have the EXACT SAME IMPULSE :smalleek: looks like the D&D designers did know what they were talking about after all.

Of course, there's arguments to be made for heavier weapons smashing through armour better and lighter weapons being harder to block through their speed, but now we're getting out of the realm of first-year mechanics...

[Spiryt]

All those equations are lacking biology element though - human armed with two times lighter sword won't move his arm, (and sword in result) nowhere close to 2 times faster, compared to 'average' ones.


Close to 1.5, maybe but that's top.

Coupling with issues about dissipation of all that energy etc. lighter sword just cannot be used to hit nearly as hard as heavier one.

"Lightweight" swords were obviously used - like this long, yet fine beast (http://www.myarmoury.com/feature_alexandria.html) - for ability to maneuver, change directions rapidly etc.

But making them out of half as dense material wouldn't have sense anyway.

[Togath]

Perhaps -1 to hit and/or -1 to damage against targets wearing armour, but the weapon counts as one category lighter for weapon finesse or twf, and the weapon counts as silvered?
The lower damage/lower chance to hit would help simulate the fact that a lighter, but faster weapon would work reasonably well on unarmoured targets, but have less ability to penetrate armour, and the lighter category would help simulate the fact that you can move it faster(using weapon finesse), and that it's easier to hold in one hand(twf).

[Seerow]

Perhaps -1 to hit and/or -1 to damage against targets wearing armour, but the weapon counts as one category lighter for weapon finesse to twf, and the weapon counts as silvered?
The lower damage/lower chance to hit would help simulate the fact that a lighter, but faster weapon would work reasonably well on unarmoured targets, but have less ability to penetrate armour, and the lighter category would help simulate the fact that you can move it faster(using weapon finesse), and that it's easier to hold in one hand(twf).

So you'd have a mithril spiked chain that you could wield 1-handed and still get all the benefits for only a -1 to damage? Making one handed weapons count as light for finesse and two weapon fighting seems fine, but bringing two handed weapons down to 1 handed seems potentially troublesome.

[Hiro Protagonest]

So you'd have a mithril spiked chain that you could wield 1-handed and still get all the benefits for only a -1 to damage? Making one handed weapons count as light for finesse and two weapon fighting seems fine, but bringing two handed weapons down to 1 handed seems potentially troublesome.

Well, kusari-gama is core, even if it is eastern flavored. They deal about the same damage (1d6, 2d4-1), and it's one-handed for all intents and purposes so you don't even get the PA and 1-1/2 strength bonus to damage.

[georgie_leech]

Personally, I rule that mithril weapons increase the effectiveness of weapons if they're not meant for brute strikes (i.e. any finessable weapons). The point of a rapier isn't to stab through the enemies shield, it's to parry, dodge, spin, (ha!) thrust through a gap or other vulnerable area. Thus, being able to move the weapon more easily makes it easier to use effectively. The bonus I give is +2, as well as doubling the effect of any weapon focus etc. feats. Doesn't come up often, but it's there as a nod to those who actually do make a point of being better than other people with a weapon.

[Nerd-o-rama]

All those equations are lacking biology element though - human armed with two times lighter sword won't move his arm, (and sword in result) nowhere close to 2 times faster, compared to 'average' ones.


Close to 1.5, maybe but that's top.

Coupling with issues about dissipation of all that energy etc. lighter sword just cannot be used to hit nearly as hard as heavier one.

"Lightweight" swords were obviously used - like this long, yet fine beast (http://www.myarmoury.com/feature_alexandria.html) - for ability to maneuver, change directions rapidly etc.

But making them out of half as dense material wouldn't have sense anyway.

Yeah, that's basically the problem here. Halving mass does not mean that velocity or the delta-V (and therefore delta-impulse) when you hit something is doubled. It does mean that your arm only has to exert half as much force to achieve the same initial acceleration of the weapon, but that initial acceleration doesn't matter nearly as much as the weapon's final velocity when it hits the target, which unless you're taking a very, very short swing is going to cap out at a constant value, due if nothing else to the mechanics of the human arm and the kinds of times and distances we're talking about here.

[jaybird]

All those equations are lacking biology element though - human armed with two times lighter sword won't move his arm, (and sword in result) nowhere close to 2 times faster, compared to 'average' ones.


Close to 1.5, maybe but that's top.

Coupling with issues about dissipation of all that energy etc. lighter sword just cannot be used to hit nearly as hard as heavier one.

"Lightweight" swords were obviously used - like this long, yet fine beast (http://www.myarmoury.com/feature_alexandria.html) - for ability to maneuver, change directions rapidly etc.

But making them out of half as dense material wouldn't have sense anyway.

How quantifiable is that, though? Remember, we're talking about the system where g=0 and falling is at a CONSTANT RATE...compared to that, the abstractions that my calculations make are barely noticable.

[Togath]

So you'd have a mithril spiked chain that you could wield 1-handed and still get all the benefits for only a -1 to damage? Making one handed weapons count as light for finesse and two weapon fighting seems fine, but bringing two handed weapons down to 1 handed seems potentially troublesome.

the phrasing was due to a typo that my spell check missed, what I meant was that for twf a mythril one handed would count as light, I just phrased it oddly due to having been tired a the time and due to a typo, and for weapon finesse it would count as lighter , but that wouldn't allow two handed weapons to be finessed(unless one stated that it coud be).

[Snowbluff]

How quantifiable is that, though? Remember, we're talking about the system where g=0 and falling is at a CONSTANT RATE...compared to that, the abstractions that my calculations make are barely noticable.

Oh no no no. Everything falls at the same rate, but the heavier weapon has more FORCE, as opposed to just VELOCITY, when falling.

[crazyhedgewizrd]

Wow people fight over 4lbs vs 2lbs for a sword, when in the greater sense it doesnt mean much. Differance between longword and shortsword is on avg 1 point of damage, just put a -1 damage like silver and make it finesse.

[Togath]

good point, I hadn't actually thought of that, also I should have taken a look at the weight of weapons before sayng anything, 12lb vs. 6 lb isn't that large of a difference(and that's for the heaviest weapons in the phb)

[Agent 451]

Could someone explain to me why everyone is keeping the force exerted by the arm constant? Simplicity?

[Zaq]

Could someone explain to me why everyone is keeping the force exerted by the arm constant? Simplicity?

You're lucky they're not assuming your arm is a sphere.

[crazyhedgewizrd]

Could someone explain to me why everyone is keeping the force exerted by the arm constant? Simplicity?

Its the assumption that you can move your arm at twice the speed with a weapon that weights half as much.

[Ernir]

You're lucky they're not assuming your arm is a sphere.
But they are assuming the sword is a something like a point mass. :smallbiggrin:

[ericgrau]

I would think that an axe, mace or bludgeoning weapon would lose damage but not a sword, since a lot of their damage is dependent on weight. Though really those shouldn't be mithril in the first place. Swords were fluted to reduce their weight on purpose.

As long as a sword is rigid and sharp I imagine the force exerted for a piercing blow is dependent mostly on the arm strength and would be almost the same even starting at zero speed upon contact with flesh. Not on momentum built up during the swing, unlike a heavier bludgeoning weapon which cannot be so easily thrust through the body if it starts at zero speed in contact with the target.

Motion physics alone don't describe arm swings or motors very well because they put out more energy at an ideal speed and weight. 1/10th the weight doesn't mean 10 times the acceleration because the arm simply won't go beyond a certain velocity.

Beyond that maybe something should be done but the system doesn't support such things very well. Someone with a strength of 40 can't wield a longsword as a light weapon either. That's part of the cost of not making things more complicated than they are. And that's where homebrew comes in.

[Seharvepernfan]

I ruled that a mithril finessable weapon grants a +1 competence bonus on attack rolls if you use weapon finesse with it. I also ruled that a longsword made of mithril becomes finessable, even two handed.

[Gnoman]

I went in a completely different direcdtion with my homebrew. In mine, mithril widened the critical range by one step (this stacks with keen/improved critical as an exeption to the standard rule) but reduced the multiplier by one. (x2 weapons no longer dealt bonus critical damage, but could still score crits for any other purpose, such as flaming burst.) Likewise, adamantine did the opposite, narrowing the range and increasing the multiplier.

[Hylas]

I'm tired because I just finished a physical chemistry midterm, and white wine, but hey, I'll try to do some thinking if it means I can combine physics, 3.P, and homebrew.

Assuming the force you can swing a sword with is constant (your arm is the same strength while using both swords), the swords are the same physical size (both longswords, same arc length on a swing), and the mithril one has half the mass (1/2 weight), then whichever one has the most energy behind the swing will do the most damage, right? For that we'll use kinetic energy because, hey, kinetic energy.

1/2*mass*(velocity^2)

Since people agree that mass is halved and velocity is doubled (force is constant) then a steel sword (m=1, v=1) would do 1/2*1*1=1/2 units of energy. A mithril sword (m=1/2, v=2) would do 1/2*1/2*(2^2)=1 units of energy. A mithril sword would have twice as much kinetic energy as a steel sword with the same strength swing behind each. This is because mass is linear and velocity is squared in the function. Squaring is awesome.

This does not take into account the limit at which a person can swing an object, which direction a swing is being done in (overhead, side, etc), gravity, ambient magic, what kind of coffee the swinger had that morning, poor dice rolls, and GM hate for the player. Some factors favor the heavier object, most favor the lighter one.

Another point that someone has been arguing is that a heavier object moving at the same speed as light object will do less damage. This is also true.

~~~

As for house rules I would say that mithril would count as silver and would become a size easier to wield (one handed to light, two handed to one). Maybe all of them can be finesse-able. Mithril weapons are expensive and mundanes deserve nice things.

[crazyhedgewizrd]

to get the same force you would a velocity of about 1.4x steels velocity.

[Rion]

I'm pretty sure that a human with some strength don't swing a 2-2,5lb object anywhere near twice as fast as a 4-5lb (and that's heavy for a onehanded sword) object.

[Ast]

I can't believe no one said this before, but it's mithral :smallbiggrin:

Mithril: nigh-indestructible (as I remember it) material that originated from LotR
Mithral: lighter than steel material from D&D :smallsmile:

[Ashram]

I can't believe no one said this before, but it's mithral :smallbiggrin:

Mithril: nigh-indestructible (as I remember it) material that originated from LotR
Mithral: lighter than steel material from D&D :smallsmile:

Or, if we're going Final Fantasy, it's mythril. Anyways.

[Ast]

While we're at it, did Salvatore use "mithril" or "mithral" in his books? I have only Polish version and there is "mithril". I don't know if this is just creative work by some semi-competent translator or if this originated from the author ;)

[Seharvepernfan]

Admit it, "Mythral" looks the coolest.

[panaikhan]

I prefer Mercurial, but that's a whole other story.
Can you have a Mithral Mercurial Longsword? That might hurt :)

[Averis Vol]

so, i am 100% lost on all this math. but i'll put in my point as a swordsman anyways. when i fight with the different categories of weapons theres a difference that not even weight can change. when using a weapon of the "one handed" category something you need to remember is length.

even if i were to take my longsword (which is about 5 lbs.) and make it as light as one of those crappy aluminum show swords, i could swing the sword harder but the effect would be that this new sword (the 2.5 lbs. one) just doesnt have the extended weight of its own to do any damage. an example would be if i were swinging against, say a 4x4, the light blade if swung in a horizontal arc would bite in about a quarter inch. i believe this is due to the fact that a lighter weapon, even if swung with the same arm as a heavier blade, doesn't have the building momentum required to drive the weapon after its stopped its travel through the air. now, if i were to grab something like a scimitar or a cutlass, who's basic composition is is about a foot shorter and more compressed, the outcome is a bit different only because the striking point is situated closer to the arm. i think what i'm trying to say is that more then weight, length is a determining factor of damage. thats why bigger weapons do more damage. also, its much easier to parry a light weapon, seeing as when two weapons collide, the heavier one will almost always push back on the lighter, not the other way around.

so in summary: if you make a sword mithral i think you should change it from slashing to slashing/piercing. because the lighter the weapon, the more likely you are to be using it to stab then slash or parry. i guess i could also see letting a mithral one handed sword to be used with finesse, like the rapier, and still retain the ability to power attack. but seeing as mithral is as strong as steel i don't agree with the -1 damage for silver, since it only gets the -1 due to the instability of the alchemical process used to create it.

[Snowbluff]

I'm tired because I just finished a physical chemistry midterm, and white wine, but hey, I'll try to do some thinking if it means I can combine physics, 3.P, and homebrew.

Assuming the force you can swing a sword with is constant (your arm is the same strength while using both swords), the swords are the same physical size (both longswords, same arc length on a swing), and the mithril one has half the mass (1/2 weight), then whichever one has the most energy behind the swing will do the most damage, right? For that we'll use kinetic energy because, hey, kinetic energy.

1/2*mass*(velocity^2)

Since people agree that mass is halved and velocity is doubled (force is constant) then a steel sword (m=1, v=1) would do 1/2*1*1=1/2 units of energy. A mithril sword (m=1/2, v=2) would do 1/2*1/2*(2^2)=1 units of energy. A mithril sword would have twice as much kinetic energy as a steel sword with the same strength swing behind each. This is because mass is linear and velocity is squared in the function. Squaring is awesome.

This does not take into account the limit at which a person can swing an object, which direction a swing is being done in (overhead, side, etc), gravity, ambient magic, what kind of coffee the swinger had that morning, poor dice rolls, and GM hate for the player. Some factors favor the heavier object, most favor the lighter one.

Another point that someone has been arguing is that a heavier object moving at the same speed as light object will do less damage. This is also true.

~~~

As for house rules I would say that mithril would count as silver and would become a size easier to wield (one handed to light, two handed to one). Maybe all of them can be finesse-able. Mithril weapons are expensive and mundanes deserve nice things.

Thank you!

[ericgrau]

The physics here is ignoring the efficiency of arms propelling different speeds and masses. The reality is for building up momentum arms will be most efficient and do the most damage swinging a certain mass, not less or more. At a lighter weight you won't get the same force from the arm and you'll in fact do less damage.

Otherwise you could swing a 1 oz. sword at 500 mph and do the most damage that way, but arms simply can't do that even if it requires the same force.

[Madeiner]

Here's my take.

Why is it necessary that a mithril weapon be better than a steel one?
Each material has it's application.

Make your car out of gold, and other than costing a lot of money, you don't get any benefit.

Make some electrical junction out of gold, and you have a cleaner signal (i think)

Mithril is good for armor and shields; doesn't have to be good for everything.

[Novawurmson]

But what if a Wizard changes the speed of light in a vacuum in the campaign world?

[ericgrau]

Here's my take.

Why is it necessary that a mithril weapon be better than a steel one?
Each material has it's application.

Make your car out of gold, and other than costing a lot of money, you don't get any benefit.

Make some electrical junction out of gold, and you have a cleaner signal (i think)

Mithril is good for armor and shields; doesn't have to be good for everything.
You are correct because gold resists corrosion far better than copper yet conducts electricity just as well or slightly better. At first you wouldn't notice the difference, until the copper contact corrodes a few years later. In fact these contacts are usually gold-plated copper to save money without losing protection (unless the plating is thin and wears off).

Personally I wouldn't increase the damage on mithril heavy weapons because they need to have a specific weight to work best. I might employ one of the above house-rules on other weapons though.