Somebody recently told me that chainmail was the most effective armor against arrows, not plate as was often said, which is amusing since the "common wisdom" always held that chain was worst (the point of the arrow finding the "holes" in the mesh, supposedly." That someone said it was because the chain has a bit of "give"' in it and catches the arrowhead like a net- which is exactly how Kevlar weave stops modern bullets. Sounds like another example of historians who know jack about ballistics or the concept of modern testing making empirical statements again. -.-
In terms of
pure protective capabilities, mail really wasn't that far behind plate.
The absolute #1 advantage of plate armor is maneuverability. A mail hauberk has every single ounce of weight hanging from your shoulders. Plus, to get decent protection against blunt trauma you needed about 4" of padding, minimum. So mail was incredibly fatiguing and hot to fight in.
Plate, in contrast, spreads the weight out over the body (and a full set of later plate armor weighed about the same as a mail hauberk, about 60 pounds), and doesn't need hot, insulating padding. Warriors in plate were maneuverable enough that King Henry III would do somersaults and cartwheels in full armor, to entertain guests.
I haven't looked at armor that closely, but 40D, anyway, had the exact opposite. Of course, it could very well be that dwarven plate is overengineered and tremendously thick compared to human stuff.
Anyway, though, chainmail
was pretty much proof against arrows. But then, so was plate. You may've seen recent "research" on whether bodkin points could pierce plate, but that study was very unrealistic. The guy that did it even acknowledged that the carbon content (and thus hardness) of the bodkin points used were
far in excess of any known historical example. That's led a lot of people to the wrong conclusion about arrows vs. armor. Historical examples of bodkin points are made out of metal that's softer than what plate armor was made from, so their chances of punching through a plate, even on a perfectly aligned close range shot, was slim to none.
Bodkins really weren't effective against mail armor, either. The logic goes that maybe a bodkin point could slip into a ring and force it apart, but at realistic combat distances, the arrow doesn't have anywhere near enough weight or velocity to do that. It's far more likely that bodkins were simply a point that was very easy to mass-produce, a good design to find small gaps in armor (especially around the visor), and would be much more effective against boiled leather armor, like a fellow peasant-soldier might wear, at long range. Historically speaking, though, the majority of armored knights who were killed by arrows, were shot in the face while their visor was up.
Some people also like to cite the battles of Agincourt and Crecy when discussing the effectiveness of arrows vs. plate, but French tactics in both cases were so
utterly moronic, that it was
physically impossible for the English to have lost either time. The
worst the English could've done would have been a tie, and that only if they had committed mass suicide! Even a retreat would have resulted in piles of dead French knights at the bottom of a bog.
No, the English were victorious in those battles not due to any real advantages of the longbow, but because the French were idiots (they also disobeyed orders from their king, saying to hold back, both times). They thought, first of all, that a knight on foot would be just as effective as a knight on horseback (big surprise, they weren't). And second, they thought that a 3 foot deep muddy bog was perfectly safe for a guy with 60 pounds of steel to wade through (how could
that ever go wrong?). And third, they thought that no adjustment of tactics whatsoever was necessary to compensate for the lack of horses or bad terrain, like they insisted on sending their crossbowmen out without whatchamacallits (those portable shield things that you can hide behind while reloading).
The majority of actual "kills" (as opposed to technical suicides) of French knights, in both battles, were actually inflicted by billhooks and other hand weapons, on Frenchmen who had been "lucky" enough to fall on their backs in a shallow spot, but who still couldn't get up because of the mud. Arrows were mainly useful for taking out French crossbowmen, and that because they had been sent out without their shields.
Anyway, though, I guess it is technically true that mail armor stops arrows the same way that kevlar stops bullets. But that has little to do with anything, given that plate also made the wearer virtually immune to arrows, as long as they kept their visor down (but it's impossible to shout orders without raising it).
Arrows probably should have hella more velocity, for example. It'd be very interesting if you could make lead arrows that were even more effective against unarmored targets because of their greater density (there's a reason sling bullets were made of lead,) but fare poorly against heavily armored opponents.
Definitely a good idea to figure out an appropriate velocity for arrows. It's also silly that blowguns top out higher than bows and crossbows, when it's the opposite. Sure, you can "blow harder," but that doesn't change the fact that air can only move at a certain speed when lungs are pushing it out, and a dart will never move faster than the air shoving it. A sneeze goes at about 100 mph, while an arrow shoots at more like 200 mph, so a speed limit of 100 for bows and 1000 for blowguns is just ridiculous.
Anyway, lead-tipped arrows wouldn't do too well, but arrows with lead weights on them wouldn't be too bad an idea at all, for close-range shooting. Roman pila often had lead balls near the tip, to increase their penetrating ability. As long as the lead weight is smaller than the arrowhead, a weighted arrow would be better against armor, too, at very close range (but poorer at long range).
Going back to the armor, there's already an interesting balance set up- if we give chainmail a bonus against arrows (if that's possible with the new system,) they'll be preferable to plate against ranged enemies, but be inferior in close combat. And naturally, if you have chainmail UNDER plate, you get an armored beast of a soldier, but a very slow one, not to mention only epic dwarves would be able to move around under that load anyway.
Well, the balance I see is sort of different. For one thing, there's the skilled vs. unskilled labor thing I mentioned. It'd be a great game balance thing if certain items were easier for novices to make, but had less effect due to quality. I.e., a novice would make very acceptable chainmail, and a legendary armorsmith's chainmail would only be a little bit better. But the novice would make atrocious and unwearable plate armor, while the master would make really great armor.
Then the maneuverability difference. That could be done by having customizable armor coverage of body parts (I keep getting stabbed in the upper arms, argh! I need arm armor!), and also how much "load" is put on certain areas. A mail hauberk would cover the torso, upper arms, and upper legs, but all the weight would rest on the shoulders, making it very fatiguing to wear and hard to maneuver in. But plate armor would be made of multiple smaller parts that attach to different body parts.
For "doubling up" on armor, there actually is a strong historical precedent there, in the time after the black plague where better protection was needed, but the plate armor industry wasn't in full swing yet. Usually they would wear a mail hauberk without the padding underneath, then put a breastplate, cuirass, brigandine, etc., over top of it. Usually they would try to make the outside piece tight enough at the waist that the hips would support most of the weight; that would also "trap" the mail against the body, so that the "skirt" protecting the legs would also hang from the hips, making the weight distribution a little bit better. Add gauntlets, greaves, sabotans (I think they were called?), and a better helmet, and you would pretty much have the same protection as full plate, but it would weigh probably around 20 pounds more, and have poorer distribution.
That could result in some very interesting gameplay tradeoffs. Low-level smiths could make much higher quality mail than plate, but low-level warriors would have a much tougher time fighting in mail than plate.