Shield Bonus

A shield bonus is added to a character's Armor Class (AC), and stacks with other kinds of bonuses to AC, but not with other shield bonuses.

As the name implies, the most common source of a shield bonus happens when a character wields a shield. However, some weapons grant a shield bonus (such as the Scizore, and the Glaive) when used (or not used) in a particular way. A few other methods exist to gain a shield bonus, as well, such as spells, feats, etc. In all cases, if multiple sources of shield bonuses are available to a character, only the highest available bonus is used.

If a shield is enchanted with an enhancement bonus, the enhancement bonus is added directly to the shield's base shield bonus to AC, for purposes of determining the total AC provided by the shield. Thus, a +3 heavy steel shield, which has a base shield bonus to AC of 2, has a total shield bonus of 5 (adding the +3 enhancement bonus). The weapon is still described as a +3 shield (not a +5 shield), since enhancement bonuses can only go up to +9, and the cost of the enhancement bonus is based on the plus provided. It is also a descriptive indicator of the shield's magical power.