You are skilled at dodging past opponents and avoiding blows.
Prerequisites: Dex 13, Dodge.
Benefit: You get a +4 dodge bonus to Armour Class against attacks of opportunity caused when you move out of or within a threatened area. A condition that makes you lose your Dexterity bonus to Armour Class (if any) also makes you lose dodge bonuses.
Dodge bonuses stack with each other, unlike most types of bonuses.
Special: A Fighter may select Mobility as one of his fighter bonus feats.
Source: Player’s Handbook (Page 98)