MDGs Fantasy AGE Game - Where there's smoke
Serpentine: devil's powder, black powder, gunpowder
The formula for gunpowder was "discovered" (likely imported) by the alchemist's guild who have kept it a closely guarded secret. A pact with the Blackstone Dwarves gave access to the raw materials to make it in bulk. The King retains sole right to purchase it in bulk to keep his armies fortified, ostensibly to protect the boarders of the kingdom. It is relatively easy to come by in smaller, personal amounts, but hard to acquire enough to supply even a small troop.