Bonebrack is a material composed of various colored fused and fossilized bones of fiendish creatures of chaotic evil alignment. If the tales are correct, it was made by an undead demon, the first of his kind. He gave up some of his four base energies, chaos, evil, life, and fire, replacing that sacrificed with negative energy. One legend says that the demon becoming an undead was the only way to complete the experiment, and create bonebrack.
Each of his footfalls makes the sound of creaking bone striking stone. It's an eerie sound made by his armor, not by him. His armor, forged by his own hand, is made of bonebrack. It's a material composed of multicolored fused and fossilized demon bones. The older and more powerful the demon, the stronger the bones. To be effective, heavy armors and shields require bones from demons that lived over three centuries. This is a long time for demons; such is the hardship of the Abyssal worlds.
Bonebrack was invented by an undead demon, the first of its kind. The demon gave up some of his four base energies, chaos, evil, life, and fire, replacing that sacrificed with negative energy. Becoming an undead was the only way he could handle stuff toxic to the living.
- from the Godspawn Saga
Bonebrack periodically releases static electricity. In some magic items this can add charges to them or be contained so that it can be discharged; for items with charges and having a electrical attack form, this equates to 1 charge per week.
One of the largest concentrations of bonebrack on the world Bal-Kriav is at the ruin Valefor. When enchanters seek to make necromantic and or evil magic items they like to use this stuff. This is because bonebrack absorbs magical enchantments like a sponge, reducing enchanting costs by 20% and time to build by 10%.
Bonebrack is destructive to natives of the Mortal Systems. When touched to the flesh of mortals, it causes 1 hit point of vile damage. Bonebrack has another property which is very useful to undead that like to use weapons. A weapon that has bonebrack from hilt to tip allows undead to use their life draining, paralysis, energy draining, and other baleful touch attacks through the weapon. For example, a lich wielding a bonebrack spear would be allowed to use its touch attack when it hits with the weapon.