Which doctrine prevents one party from taking unfair advantage of another through deceptive language or conduct?

The doctrine that prevents one party from taking unfair advantage of another through deceptive language or conduct is known as Equitable Estoppel. This legal principle is based on the idea that when one party induces another to rely on certain representations or conduct, and the relying party acts on that reliance to their detriment, it would be unfair to allow the first party to contradict or deny the truth of their original assertions.

In the context of surveying or land use, this may involve situations where a surveyor provides information that a landowner relies on to make decisions. If the surveyor later contradicts that information, the landowner may experience harm due to that reliance, thus triggering Equitable Estoppel to prevent the surveyor from denying the initial representation.

The other doctrines presented have distinct applications and purposes. Patent Ambiguity deals with situations where a legal document is unclear on its face but does not directly address deceptive conduct. Defeasible Fee Simple relates to a type of property ownership that can be revoked under certain conditions, which does not involve issues of deception. Laches is a legal doctrine that addresses delays in asserting a right or claim that can disadvantage another party but does not specifically tackle deceptive situations. Hence, Equitable Estoppel best fits the description of preventing unfair