Legal Definitions - adverse authority

Adverse authority refers to legal precedents (such as previous court decisions) or statutes (written laws) that contradict or weaken a lawyer's argument or a client's position in a legal case. Even if this authority is unfavorable to their client, lawyers generally have an ethical obligation to disclose it to the court, especially if it comes from the same jurisdiction and directly applies to the issues at hand. This ensures the court has all relevant legal information to make an informed decision.

• Example 1: Contract Dispute

  A lawyer is representing a small business that believes a contract clause allows them to terminate an agreement without penalty. While researching, the lawyer discovers a recent decision from the state's highest court involving a very similar contract clause and factual scenario. In that prior case, the court ruled that such a clause did not permit termination without penalty under those circumstances. This previous ruling is adverse authority because it directly undermines the lawyer's client's argument for penalty-free termination. The lawyer would need to bring this case to the court's attention, even though it hurts their client's immediate position.

• Example 2: Environmental Law

  A legal team is defending a manufacturing company accused of violating a state environmental regulation regarding wastewater discharge limits. The company argues that the regulation's wording is ambiguous and allows for a higher discharge level under certain conditions. However, the legal team uncovers an administrative ruling from the state's environmental protection agency, issued just a few years prior, which specifically interpreted that exact regulation in a way that prohibits the company's current discharge levels. This administrative ruling serves as adverse authority because it provides a clear, unfavorable interpretation of the regulation that goes against the company's defense.