Precedent is a principle or rule established in a legal case that becomes authoritative to a court or other tribunal when deciding subsequent cases with similar legal issues or facts.[1][2][3] The legal doctrine stating that courts should follow precedent is called stare decisis (a Latin phrase with the literal meaning "to stand by things decided").[4]
Common-law legal systems often view precedent as binding or persuasive, while civil law systems do not. Common-law systems aim for similar facts to yield similar and predictable outcomes, and observing precedent when making decisions is the mechanism to achieve that goal. Common-law precedent is a third kind of law, on equal footing with statutory law (that is, statutes and codes enacted by legislative bodies) and subordinate legislation (that is, regulations promulgated by executive branch agencies, in the form of delegated legislation) in UK parlance – or regulatory law (in US parlance).
Case law, in common-law jurisdictions, is the set of decisions of adjudicatory tribunals or other rulings that can be cited as precedent. In most countries, including most European countries, the term is applied to any set of rulings on law, which is guided by previous rulings, for example, previous decisions of a government agency. Essential to the development of case law is the publication and indexing of decisions for use by lawyers, courts, and the general public, in the form of law reports. A precedent is a historical setting example for the future (though at varying levels of authority as discussed throughout this article), some become "leading cases" or "landmark decisions" that are cited especially often.
In contrast, civil law systems adhere to a legal positivism, where past decisions do not usually have the precedential, binding effect that they have in common law decision-making; the judicial review practiced by constitutional courts can be regarded as a notable exception.
Stare decisis (/ˈstɛərridɪˈsaɪsɪs,ˈstɑːreɪ/ ) is a legal principle by which judges are obligated to respect the precedent established by prior decisions. The words originate from the phrasing of the principle in the Latin maxim Stare decisis et non quieta movere: "to stand by decisions and not disturb the undisturbed".[5] In a legal context, this means that courts should abide by precedent and not disturb settled matters.[5] The principle can be divided into two components:[6]
The second principle, regarding persuasive precedent, reflects the broad precedent guidance a court may draw upon in reaching all of its decisions.[6]