Certain magic items require a creature to Attune to them before they can be used. This feat permits a creature to Attune to a number of magic items at one time equal to their proficiency bonus. This feat overrides the standard limit on magic items that can be Attuned to a single creature or character. So, at level 1, creatures can Attune up to 2 items, and 3 items at level 5, 4 items at level 9, 5 items at level 13, and 6 items at level 17. 

**Note: This is a house rule that is used in my Eberron campaigns, allowing me to distribute more magic items (because getting magic items is fun!). Each creature (whether PC, NPC, or DMPC) manually adds this feat for free at the appropriate level to reflect that the number of Attunement Slots you gain varies by the Proficiency Bonus of the creature.