Warfordged

A Warforged isn't actually "living armor," though. A Warforged in 3.5E has composite plating, which provides a +2 bonus to AC, which can't stack with anything other than natural armor. This armor could be different based on their construction (by taking a feat at first level), having the composite plating be adamantine, mithral, or unarmored body (allowing the Warforged to wear armor like other PCs). This implies that the Warforged are the living construct beneath the armor, made of wood, metal, and other things, and that the armor itself is something attached to the body.

The 4E warforged function a little differently. Under the Physical Qualities header of the warforged (4E Eberron Player's Guide, p. 33), it says:


Also, in the equipment section of the Eberron Player's Guide, under Warforged Components (4E Eberron Player's Guide, p. 113), it says:


So 4E warforged can wear armor. They don't have any natural AC bonuses. They can wear regular armor if you like, or, if you'd prefer, you can have the armor attached to your warforged's body, making it impossible to remove while you are conscious.