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 Missouri, a prescriptive easement is acquired when an individual uses another's property openly, continuously, and adversely for a period of ten years. This is codified in Missouri statutes under V.A.M.S. 516.010 et seq., particularly section 516.010, which sets the prescriptive period. The use must be such that it gives the true owner a reasonable opportunity to notice the use and take action to prevent it, thus it cannot be secret or clandestine. The use must also be without the permission of the landowner, as any permission granted would negate the 'adverse' requirement. If these conditions are met, the person using the land may acquire a legal right to continue such use. It is important to note that the specifics of each situation can be complex, and the interpretation of these laws can vary by case, so it is advisable to consult with an attorney for individual situations regarding prescriptive easements.