Adverse possession—sometimes called squatter's rights—occurs when a person or entity who does not own a certain piece of real property occupies or uses it in a way that is adverse to the owner of the property—meaning the use is in conflict or at odds with the property owner’s interests.

If this adverse possession or use of the property meets the legal standard for adverse possession—often described as use that is continuous, exclusive, hostile, open, and notorious—and continues for the prescribed period of time (usually specified in the state statute)—the person or entity adversely possessing or using the property will acquire ownership of the property (title). This ownership will result in the changing of boundary lines.

Because the required adverse possession must be open, obvious, and adverse to the owner’s interests, title may only be acquired by adverse possession to the portion of property that is used in that way.

Adverse possession laws vary from state to state and may be located in a state’s court opinions (also known as common law or case law) or, more often, in its statutes.

In Alaska, adverse possession laws allow a person to acquire legal ownership of a property by possessing it in a manner that is hostile, actual, open and notorious, exclusive, and continuous for a statutory period. The statutory period in Alaska is 10 years, as per Alaska Statute 09.10.030. This means that if someone occupies another's land for at least 10 years in a way that is obvious to the owner and the public, does not have the owner's permission, and treats the land as their own, they may be able to claim legal title to that property. The claimant must also pay the property taxes during this period to qualify for adverse possession under Alaska Statute 09.45.052. It's important to note that adverse possession is a complex area of law and anyone considering or contesting a claim of adverse possession should consult with an attorney to understand the specific requirements and legal implications.