Lesser Amulet of the Master (NWN)

Ciressa Gind'ra was a mage who infiltrated the Night Masks for the Harpers, before she was found drowned in a two-inch puddle outside her residence. To infiltrate them, Ciressa created an amulet that allowed her to mimic the abilities of a master thief. One night she used it to break into the Night King's private quarters. She didn't anticipate the Night King's personal guard, who had a permanent detect magic spell surrounding the room. When the Night King was finished with her, he took the amulet and since it had qualities useful for any adventurer, he made copies of it, which he did throughout the land.