A prescriptive easement—also known as an easement by prescription or an adverse easement—is an easement (right to use property) created by a use of property (the servient estate) that is open, continuous, and adverse to the owner of the property (the servient estate).

To satisfy the requirement that the use be continuous, the use must take place over a required period of time—which may be specified in a state’s court opinions (common law or case law) or in its statutes if the state legislature has written the law regarding easements into statutes or code. If the state legislature has written a law in statutes or codes the law is said to be codified.

In Oregon, a prescriptive easement is established when an individual uses another's property in a manner that is open, notorious, continuous, and adverse to the interests of the property owner for a statutory period. According to Oregon law, specifically ORS 105.620, the required period of continuous use to establish a prescriptive easement is 10 years. This means that the person claiming the easement must have used the property in a way that was visible and apparent (open and notorious), without permission (adverse), and uninterrupted for a full decade. If these conditions are met, the user may be able to obtain a legal right to continue using the property despite the owner's wishes. It is important to note that the establishment of a prescriptive easement can be complex and may require legal action to be recognized by the courts. Property owners and those claiming a prescriptive easement should consult with an attorney to understand their rights and the legal implications.