The failure of a gift of personal property—a bequest—or of real property—a devise—to be distributed according to the provisions of a decedent's will because the property no longer belongs to the testator at the time of his or her death or because the property has been substantially changed.
There are two types of ademption: by extinction and by satisfaction.
Lundwall, Mary Kay. 1993. "The Case against the Ademption by Extinction Rule: A Proposal for Reform." Gonzaga Law Review 29 (fall) 105–32.
Volkmer, Ronald R. 2000. "Doctrine of Ademption in the Law of Wills." Estate Planning 27 (March-April): 136–37.