From DDO wiki
Docents you equip provide armor equivalent to Chainmail. This is treated as metallic light armor. You have a 15% arcane spell failure chance, -1 armor check penalty to certain skills, and a +5 maximum dexterity bonus.
- Selecting this Feat will prevent you from being able to select the Adamantine Body feat later as they are mutually exclusive.
- MRR/PRR is granted to the player when the feat is purchased. Equipping/Unequipping your docent will not change your PRR/MRR
- An Artificer may select this feat as one of his artificer bonus feats.