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 Illinois, a prescriptive easement is recognized and can be established when a person uses another's property openly, continuously, and adversely without the owner's permission for a period of at least 20 years. This concept is codified in Illinois Compiled Statutes under 735 ILCS 5/13-101, which sets the statutory period for adverse possession, and by extension, prescriptive easements. The use must be such that it would give the owner a reasonable notice of the claim. It's important to note that the use must not be secretive or done with the owner's consent, as this would not meet the 'adverse' requirement. If someone believes they have a claim to a prescriptive easement, they would typically need to file a lawsuit to have the easement legally recognized. An attorney can provide specific guidance and representation in such matters.