What does estoppel prevent in legal cases?

Estoppel is a legal principle that prevents a party from arguing something contrary to a claim made or position taken previously, especially when that claim or position has been established by a court's decision. This means that if a particular issue has already been adjudicated and determined in a previous case, parties involved are barred from relitigating that same issue in future proceedings. This principle upholds the integrity of the judicial system by ensuring that once a decision has been made by a competent authority, it should not repeatedly be contested, thus promoting finality and certainty in legal matters.

While it may seem beneficial for litigants to introduce new evidence, pursue appeals, or seek settlement agreements, estoppel specifically relates to the consistency of legal arguments regarding already decided matters. This focus on maintaining the outcomes of prior judgments is critical to preventing unnecessary litigation and fostering trust in legal decisions.