Adverse possession is an anomaly in the law in that it is a system whereby a legal right is obtained through conduct which must be wrongful. Essentially it consists of the nonpermissive occupation of another's land until a statute of limitations bars his right to recover it. Unlike the usual statute of limitations situation, in which only a remedy is barred, in adverse possession the occupant acquires an affirmative legal right, an original title in fee simple. Clearly such a strange and drastic doctrine must spring from strong necessity. Desire to reward the occupant or punish the lax owner should not be the motive, though some cases smack of this. The doctrine arose in law, not equity; so estoppel is not the explanation. Rather, it is suggested adverse possession rests on considerations of public policy: that title to land should not long be in doubt, that society will benefit from someone's making use of land the owner leaves idle, and that third persons who come to regard the occupant as owner may be protected. Of some force too must be the notion that mere possession, itself a rudimentary right in land, might metamorphose into a more formal right if long continued.
William B. Stoebuck,
The Law of Adverse Possession in Washington,
35 Wash. L. Rev. & St. B.J.
Available at: https://digitalcommons.law.uw.edu/wlr/vol35/iss1/3