What does estoppel prevent in legal terms?

Estoppel is a legal doctrine that prevents a party from denying a fact that has already been established, especially if that denial would be detrimental to another party who relied on the established fact. The essence of estoppel is to uphold fairness and prevent inconsistency in legal arguments and claims. For example, if one party has made a representation or has acted in such a way that another party has relied on that representation to their detriment, the party who made the representation cannot later deny the truth of that representation.

This principle is crucial in various legal contexts, especially in contract law and property law, as it helps maintain trust and reliability in transactions and interactions. The other options, while potentially capturing aspects of legal relationships, do not accurately define the primary function of estoppel in preventing a party from denying a fact that has been established through their own previous actions or statements.