Armory shield upgrades affect the pierce armor of all human soldiers, heroes, and ships: those trained at the Academy, Barracks, Military Barracks, Counter Barracks, Longhouse, Dock, Migdol, Fortress, or Hill Fort. They do not affect myth units or siege weapons. Pierce armor protects a unit against pierce attacks, which are generally ranged attacks such as arrows. The armor percentage is the amount by which the attack is reduced.

As the first available metal, copper was used to emboss wooden shields. Copper not only improved the strength of the shield, but also provided a great aesthetic appeal. Copper on shields disappeared quickly when the new technology of bronze was discovered and existing copper was consumed to make the stronger new metal.