Nullum Tempus Act

Adverse possession, sometimes colloquially described as "squatter's rights", is a legal principle that applies when a person who does not have legal title to a piece of property—usually land (real property)—attempts to claim legal ownership based upon a history of possession or occupation of the land without the permission of its legal owner.

In general, a property owner has the right to recover possession of their property from unauthorized possessors through legal action such as ejectment. However, in the English common law tradition, courts have long ruled that when someone occupies a piece of property without permission and the property's owner does not exercise their right to recover their property for a significant period of time, not only is the original owner prevented from exercising their right to exclude, but an entirely new title to the property springs up in the adverse possessor. In effect, the adverse possessor becomes the property's new owner. Over time, legislatures have created statutes of limitations that specify the length of time that owners have to recover possession of their property from adverse possessors. In the United States, for example, these time limits vary widely between individual states, ranging from as low as five years to as many as 40 years.

Although the elements of an adverse possession action are different in every jurisdiction, a person claiming adverse possession is usually required to prove non-permissive use of the property that is actual, open and notorious, exclusive, adverse, and continuous for the statutory period.

Personal property, traditionally known as "chattel", may also be adversely possessed, but owing to the differences in the nature of real and chattel property, the rules governing such claims are rather more stringent, and favor the legal owner rather than the adverse possessor. Claims for adverse possession of chattel often involve works of art.

In Roman law, usucapio laws allowed someone who was in possession of a good without title to become the lawful proprietor if the original owner didn't show up after some time (one or two years), unless the good was obtained illegally (by theft or force). Stemming from Roman law and its successor, the Napoleonic Code, adopted as the basis of law in France, Belgium, Italy, Luxembourg, Portugal, Spain, and also, in part, by the Netherlands and Germany, adverse possession generally recognizes two time periods for the acquisition of property: 30 years and some lesser time period, depending on the bona fides of the possessor and the location of the parties involved.

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Wikipedia