What are Armor and AC?
Armor Class (AC) is a measure of the natural protective ability of your equipment. The higher the number on the item you are using, the better protection it provides. Armor is a measure of protective ability applied due to its magical properties. It carries the same weight as AC, but is negative, and the lower the number of the item you are using the better protection it provides. For example, if an item has AC+2 and Armor5, the total benefit is 7 AC points.