If the real Amulet is left in a bones file, it gets converted to a fake amulet when the file is loaded . It has no effect when worn. It can be considered one of the most useless items, next to iron chains. However, it can be polymorphed into a more useful amulet. If not identified, the cheap plastic imitation can be distinguished from the real Amulet of Yendor by trying to put it into a container: the real amulet will resist.