Mithral

Mithral
Mithral is a very rare silvery, glistening metal that is lighter than iron but just as hard. When worked like steel, it becomes a wonderful material from which to create armor and is occasionally used for other items as well. Most mithral armors are one category lighter than normal for purposes of movement and other limitations. Heavy armors are treated as medium, and medium armors are treated as light, but light armors are still treated as light. Arcane spell failure chances for armors and shields made from mithral are decreased by 10%, maximum Dexterity bonus is increased by 2, and armor check penalties are lessened by 3 (to a minimum of 0).

An item made from mithral weighs half as much as the same item made from other metals. In the case of weapons, this lighter weight does not change a weapon’s size category or the ease with which it can be wielded (whether it is light, one-handed, or two-handed).

Weapons or armors fashioned from mithral are always masterwork items as well; the masterwork bonus to armor check penalty is included in the bonus given below.

Mithral has 30 hit points per inch of thickness and hardness 15.

Summary:

 * 1/2 standard weight (The DDO tooltips say the weight is 1/2. However, the actual weight is still normal)
 * -10% Arcane Spell Failure (to a minimum of 0)
 * 3 reduction to Armor Check Penalty for armor (to a minimum of 0)
 * +2 increase of the Max Dexterity modifier.