v0.31 Talk:Metal

Despite having copper, bismuth, and tin, I can't seem to make bismuth bronze. Despite having copper, gold, and silver I can't seem to make black bronze - are these broken or merely different? --Squirrelloid 09:33, 4 April 2010 (UTC)

Nevermind, my smelters were slower than i thought, and they'd only smelted 1 copper total so far. *cracks whip* get back to work you lazy bums! --Squirrelloid 10:01, 4 April 2010 (UTC)

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Impact elasticity: Used for blunt-force combat; lower is better. This is the raw value.

How sure are we about this? It seems to contradict: "Force from blunt weapons can transcend layers. For instance, a hammer can bruise the skin while breaking the bone underneath. As such, plate armor's benefits are generally ignored by blunt attacks, and leather armor would prove to be more effective." Leather as a material has a Impact Elasticity of 5000 meaning, I think, that it is much more elastic... --68.117.74.40 14:15, 8 April 2010 (UTC)

The Impact Elasticity number is based on the real life bulk modulus. The higher the number the greater the pressure that is needed to compress a material a given volume, that is it is the resistance to compressibility. Intuitively, we would think that we would want a higher rather than lower number for something like a war hammer or maul so they act less like a rubber mallet and more like a hammer. However, we don't know exactly how Impact Elasticity is used and unless we do we can't draw any conclusions about it. It would seem a little odd if it is a critical factor in a weapon as in real life it is rarely used except in gas equations as the effect is generally small for solids. Usually about 1% or less at yield strength for the metals in DF. EDIT: Just to be clear, impact elasticity shares an inverse like relationship with bulk modulus so lower "should be" better.--PencilinHand 04:36, 9 April 2010 (UTC)

I think this is more a question of how accurate the quote from the release info page is -- which is oriented towards how effectively armor can resist/absorb blunt damage before it effects the wearer. The quote suggests that leather armor would be more effective than 'plate' (metal I suppose). Let's assume that's true. While we don't know how the actual combat calculations work we can observe values the calculations use. The impact values are said to be specific to blunt damage so it's a good bet where the value that makes leather better against blunt damage is. Comparing material templates between various armor capable metals and leather, the value that stands out the most is impact elasticity (all metals have the same impact fracture/yield >> leather, which makes sense as leather isn't as durable). Impact elasticity is 635 for iron with most other metals being in that ball park and it is actually 50000 for leather. Climbing out on the branches of the speculation tree, the hypothesis is greater elasticity reduces blunt damage directly or disrupts ability of blunt damage to transmit to multiple tissue layers. Alas, a brief test of 50+ combats in the arena shows that one's dwarves might as well be naked when wearing leather against iron hammers/maces. Iron plate (and even mail as the dwarves had to wear shirts to keep their fragile, fragile upper arms in one piece) armor proved to be quite effective with almost every blow simply deflecting. So it seems that leather armor is not better than iron plate when it comes to blunt damage... at least in this specific case. --Deranged Imp 11:26, 9 April 2010 (UTC)