From the Ashes of The Great Convergence
Cold Iron Weapons
These Weapons are referred to a “Cold Iron” because they ae forged at a very low tempurature using Alchemical means to preserve their magnetic properties. These properties cause items made of cold iron to emit magnetic lines of force that are naturally disruptive to manaflux; and toxic to fey creatures and some outsiders, while being reletively harmless to those races not fueled by Mana. Cold iron can be alchemically enhanced to make it’s effects even more devestating, but this is a long and expensive process. Cold Iron weapons are now available at The Foundry due to the Expeditionay Force’s discovery and Exploitation of the Magnetic Iron Vein in Croaker Cavern. This includes ammunition such as bullets, bolts, and arrows as well! Cold Iron Weapons cost twice normal value, and can only be alchemically enhanced – Never Enchanted. Alchemically enhancing a Cold Iron Weapon or armor costs 2000 Dragons before you can even place the first enhancement on it! Masterwork weapons still cost an additional 300 Dragons to produce, and only masterwork weapons can be enhanced! Alchemically enhanced Weapons count as magical for the purpose of defeating DR. All Cold Iron Weapons cause Interference, which replaces the normal concentration rules for spellcasters and nullifies the effectiveness of Combat Casting!
An example is the Cold Iron Mace