The body of law in the United Kingdom (and other “common law” jurisdictions, such as the United States, Ireland, India and Australia) is based on law made by the government through Acts of Parliament (statute), and further developed by judges interpreting those statues to create binding precedents which future tribunals are generally bound to follow (the “common law”). The principle of common law originated in England during the Middle Ages, and most (if not all) countries which still use it today were under British influence at one time or another during their history.
Although the government is generally well advised by lawyers and jurists during the drafting stages of a Bill (it becomes an Act when it is passed by Parliament) statutory law created by these instruments is generally imprecise, ambiguous and open to interpretation. It is not until the law comes into effect, and civil and criminal cases are brought before the courts for determination that judges have the opportunity to refine and develop the law so that it becomes workable in practice. Common law is often referred to, and is synonymous with “case law”.
The decisions set precedents which other judges in similar cases will look to for guidance in making their own decisions. These precedents will be binding on the decisions of lower courts and on future cases under a doctrine referred to in legal circles as “stare decisis” (from the Latin phrase “Stare decisis et non quieta movere” – i.e. “to stand by decisions and not disturb the undisturbed.”. This doctrine forms the cornerstone of, and is a common denominator in, all common law systems.
The strength of precedent depends on two things: (a) the authority of the court handing down the decision (judgments in the lower courts and tribunals tend to carry less weight as they can be overturned on appeal, and are usually presided over by less qualified and experienced judges); and (b) whether the guidance is germane to the case (“ratio decidendi”), or whether it is a remark made in passing (such as by way of illustration). In the latter case (“obiter dictum”, or “obiter” for short) such opinion is considered to be instructive and persuasive, but not generally binding.
Where there is no precedent in the canon of domestic law (such as in England) it is not uncommon for English judges to look abroad – to derivative legal systems such as Australia and Scotland – as guidance in making their own precedent-setting decisions.
In contrast to “common law” systems, countries that operate under a Civil Code (i.e. most of mainland Europe) rely almost entirely on statute. Judges can rarely rule on a point unless there is a legislative Act behind it, and interpretation of such laws carries much less legal weight. Whereas common law systems have their origins in England, Civil Code jurisdictions evolved from Roman law principles.