Dungeons & Dragons 3.5 Feat: Dodge

You are adept at dodging blows.

Dex 13

During your action, you designate an opponent and receive a +1 dodge bonus to Armor class against attacks from that opponent. You can select a new opponent on any action.
a condition that makes you loose you Dexterity bonus to Armor Class (if any) also makes you loose your dodge bonuses. Dodge bonuses (such as this one and a dwarf's racial bonus on dodge attempts against giants) stack with each other unlike most other types of bonuses

A fighter may select Dodge as one of his fighter bonus feats (PH 38)