Equity (law)

In law, particularly in common law jurisdictions, equity is the body of law that historically developed in the English Court of Chancery, which created a set of equitable doctrines distinct from the rest of English common law.

The equitable jurisdiction of a court of equity spanned much of English private law, particularly the law of property, contract, tort, and restitution, resulting in the development of equitable principles (e.g. good faith), interests (e.g. those under trust), remedies (e.g. injunctions), and maxims, that continue to this day.

Beginning in the Medieval ages, equitable rules were historically developed largely in cases before the courts of equity, which provided relief where the inflexible legal rules of the Court of Common Pleas and King's Bench were thought to be inequitable or unconscionable. In the late 19th-century, the Judicature Acts abolished the split system of courts in England, whilst retaining the laws of equity within English common law as a distinct but complementary set of rules.

The tradition of equity as a flexible system of adjudication can be traced to the writings of Aristotle (epieikeia) and Roman law (aequitas). Later, in some civil law systems, equity was integrated in the legal rules, but in common law systems it became an independent body of law. Today, equitable legal rules exists in both civil law and common law systems as well as in international law.