Improved Damage Reduction
(Eberron Campaign Setting, page 55, DnD 3.5)
[Warforged]
You gain damage reduction or improve your existing damage reduction.
Prerequisite
Warforged
Benefit
You gain damage reduction 1/adamantine or improve your existing damage reduction by 1.
Special
If you have the Adamantine Body feat, you can take this feat multiple times.