Law is the set of rules created by a state that form a framework to ensure a peaceful society. It is enforced by the state and if the rules are broken sanctions can be imposed. The law shapes politics, economics, history and society in a variety of ways. It is often a complex and controversial subject.

In common law legal systems decisions by judges are explicitly acknowledged as “law” on an equal footing with legislative statutes, and the principle of binding precedent (or stare decisis) states that a decision made by a higher court must be followed by lower courts unless there is a compelling reason or significantly different facts and issues at play in the case. In contrast, civil law systems provide a more comprehensive set of laws, with the legislation setting out the cases that can be brought before courts and the procedures for handling claims.

The law can be broadly categorized as criminal, administrative, constitutional and civil. Criminal law covers the prosecution of individuals for a variety of offences, such as murder, robbery and fraud. Prosecution of crimes is typically dependent upon establishing three elements: the actus reus (the act or conduct); mens rea (the mental state of the individual at the time of the offense); and causation (proximate or but-for causation).

Administrative law concerns the regulations created by a government to manage public affairs, such as licensing, regulation and taxation. Constitutional law includes the protection of fundamental rights and liberties that are guaranteed to citizens by a state’s constitution or a charter. Civil law covers disputes between individuals, such as property or employment law, where the governing body is a court of justice.

There are many different definitions of law, reflecting the various schools of thought that have been influential in the development of law. Utilitarian philosopher John Austin wrote that the law is “commands, backed by the threat of sanction, from a sovereign to his subjects”. Jean-Jacques Rousseau and other natural lawyers argue that a government should be based on principles of morality.

The creation of the law is influenced by culture, tradition and legal technique. The law may be a response to social wants, as described by Roscoe Pound, or it may be a tool of coercive control. There are also differences in the approach to law between countries, with some adopting the same legal system as others and some retaining their own distinct systems. The influence of other cultures on the development of a nation’s law is also significant. The law is a complex and ever-changing concept, which serves multiple purposes: it sets standards, maintains order, resolves disputes and protects liberty and rights. A nation’s law is a reflection of the cultural values and beliefs of its people. In an authoritarian regime, the law may serve to keep the peace and maintain the status quo, but it can also oppress minorities, or promote social change without orderly process. In a democracy, the law may promote freedom of speech and religion and provide equality between men and women.