Materials
Rare metals can give weapons unsuspected properties. However, they are very expensive and hard to come by. They are often magical.
Silver
Silver weapons have a deadly effect against undead and werewolves, but against opponents with iron weapons they are almost useless and are easily destroyed. Against undead (corporeal) and werewolves they deal a damage multiplier 1 higher and reduce their AC by 5. The mere touch of silver (and thus also a hit from such a weapon) deals them 1d6 + 3 HP of damage.
A silver weapon costs as much as the original weapon plus 1 sp per 10 g of weight (approx. 8 gp per 1 kg). Making such a weapon is easier, because silver is soft and easy to work.
Silver has a hardness of 4. To determine WP and AC use the table Penetration and AC modifiers.
Dwaterg
The secret of working this dark blue metal (also called „Dwatah's gift“) is known only to dwarves and a few masters.
Making a weapon from dwaterg corresponds to making a masterwork weapon (also in time).
Products made of dwaterg are a quarter heavier than iron ones, but they are noticeably less prone to damage. They are very expensive - they cost ten times the original price plus 10 gold pieces per 1 kg of metal weight.
Dwaterg armament has quality 4 higher.
Rughaine
This almost unknown dark red metal has a remarkable property. Weapons made from it can hit even spectral (incorporeal) creatures. Armor made of this metal halves damage from a spectral attack.
On the other hand, rughaine is very soft and any harder contact with an iron weapon (armor) easily damages it (it has a hardness of 2, like silver). It is therefore suitable only for fighting incorporeal magical beings. Its price is staggering, because for 10 g of weight the buyer pays approximately 1 gp plus double the base price of the weapon (armor).
Tilion
Tilion is a light gray, light yet hard metal. It is suitable for making armor and shields, whose weight is reduced by a third without the Armor Class (shield defense) suffering, and yet its hardness is the same as that of steel.
In addition, it protects the wearer against fire; the wearer can count full AC against fire.
Tilion is more expensive than gold, and 10 grams cost around two gold pieces plus ten times the price of the original armor (the smith who uses it must succeed as when making a masterwork product).
Antamá
This very rare metal resembles silver, but is harder (about like iron, hardness 6), a little lighter and never tarnishes. It is resistant to most vitriols and lyes (up to level 5).
Its main advantage is the ability to bind magic. A magic amulet or weapon of antamá lasts practically indefinitely, temporary spells last twice as long in it, and in alchemical production the chance of success rises by +2. Antamá can be used instead of other metals than those listed in the product description.
1 gram of antamá costs about 1 gold piece. Working it is not hard (it occurs as pure metal, never as ore), but only an experienced miner can find it.
Wyvern armor
AC 7
hardness 4
difficulty 20
bonus +5 against poisons
Making this armor is very demanding and the whole procedure takes about 3 months. Besides a better AC, which is 8 for this armor, wyvern skin protects against poisons, and its wearer counts a +5 bonus to the roll against all poisons that act through the skin or are on a weapon (and the attack passes through the armor).
Manticore armor
AC 5 (leather)
hardness 2
difficulty 15
bonus +3 to MR
Making this armor is time-consuming (it takes about 3 months). The armor itself does not look any better, but the magical power hidden in the manticore remains even after its death and protects the wearer against spells and similar influences (adds +3 to MR).
Basilisk armor
AC 9
hardness 6
difficulty 25
hiding bonus +5
Only true masters can make this armor. In itself it is very hard and sturdy (and lasts as long as iron armor). Its main advantage, however, lies in camouflage, which the skin retains even after the basilisk's death, since it increases hiding (within stealth) by 5.
Dragon armor
AC 18
hardness 8
difficulty 30
bonus +10 to MR
Making this armor is the highest attainable goal of a leatherworker, since only a handful of people master this art. The armor itself is incredibly sturdy, and in addition protects very well against magic (adds +10 to MR) and even against priestly prayers (against them it gives a +5 bonus to the roll).
Silver bark
AC 7
hardness 6
difficulty 25 (woodworking)
bonus as leather (stiffness 0)
Wood elves can find and process the bark of special trees, thanks to which it gains excellent strength but keeps its flexibility and minimal weight. In this way they can make cuirasses and leggings, but not helmets.
Ironwood
Wood elves, but also some other forest peoples, can find and above all work wood so that it has almost the hardness of iron (5). Thanks to this it also gains a bonus to WP (+1/+2/+3). In addition, it can be worked in a masterly way (which is very demanding with this wood), and thereby achieve even better properties.