Armor Specialization( Player's Handbook II, p. 75)
[Fighter Bonus Feat, General]
Through long wear and hours of combat, you have trained your body to believe in its armor. Where others fl inch, you confront. When the sword falls, your instincts, born of bruises and rent fl esh, present your cuirass, cuisse, helm, or gorget to meet the blade at the perfect angle, causing it to skitter off harmlessly.
base attack bonus +12, Proficiency with selected armor type,
Choose one type of medium or heavy armor with which you are profi cient. When wearing masterwork armor (including magic armor) of that type, you gain damage reduction 2/-. Any time you lose your Dexterity bonus to Armor Class, you lose the benefit of this feat, because you cannot properly defl ect the blows of the enemy.
You can gain this feat multiple times. Its effects do not stack. Each time you take the feat, it applies to a new type of armor. A fighter can select Armor Specialization as one of his fighter bonus feats.