Advanced Construction

Prerequisites: Surgere with the Plating racial trait, Level 1 
Benefit: The Elder Ones constructed you from unusual materials for a special task of which you cannot remember, granting one of the following benefits
*Adamantine: You gain DR 1/adamantine, and may choose heavy armor as plating (rather than just light or medium armor). Your natural attacks count as adamantine for overcoming damage reduction.
*Cold Iron: Your plating's arcane spell failure chance is reduced by -15%. Your natural attacks count as cold iron for overcoming damage reduction.
*Darkwood: You gain full benefit from magical healing, and are no longer considered vulnerable to attacks which target metallic or stone creatures.
*Mithral: Your plating counts as one category lighter for determining your speed penalties and whether you can use abilities restricted by armor, such as fast movement (if your plating was light, you count as unarmored for this purpose). Your natural attacks count as silver for overcoming damage reduction. 
Special: If a Surgere ever goes through the process of changing their plating, the new plating must be made of the same special material as the Surgere's body in order to be installed. In addition these armors sometimes grant special abilities to the user and the interact with this feat in the following ways.
*Adamantine: Armor made from adamantine grants its wearer damage reduction of 1/— if it’s light armor, 2/— if it’s medium armor, and 3/— if it’s heavy armor. This replaces the damage reduction granted by this feat.
*Mithral: Spell failure chance for armor made from mithral is decreased by 10%, this does not stack with the 5% decrease from the Surgere's Plating racial trait. The maximum Dexterity bonuses are increased by 2, this also does not stack with the Surgere's Plating racial trait. The armor check penalties are decreased by 3 (to a minimum of 0), like normal armor this does not stack with the decrease to armor check penalty that is given from the masterwork property.