Exotic Armour Proficiency (Light)
( Underdark, p. 25)[General]
Choose a type of exotic armor, such as feeler plate or spidersilk (see Chapter 5: Equipment and Magic Items for a list of exotic armor types). You understand how to wear that type of exotic armor properly.
Prerequisite
Armor Proficiency of the appropriate sort (for example, you must have Armor Proficiency [Heavy] to take Exotic Armor Proficiency [feeler plate]),
Benefit
You are proficient with a specific type of exotic armor and take no armor nonproficiency penalties when you wear it.
Special
You can take this feat multiple times. Each time you take it, you must choose a new type of exotic armor.
Normal
If you are wearing exotic armor with which you are not proficient, you take its armor check penalty on attack rolls and on all Strength-based and Dexterity-based skill checks.