Adverse possession is a rule in property law. This rule says that if property is not being used by its owner while another person is using the property, this other person (called an "adverse possessor") becomes the new owner of the property. To get these rights, the adverse possessor usually must use the property in the way a normal owner would do for a period of time, typically 20 years. In some jurisdictions, a form of adverse possession exists in which the adverse possessor ends up with sharing some rights to property with the owner, such as a right-of-way, instead of getting all the rights.