Common law offence

A common law offence is a crime defined by judicial precedent rather than by an act of a legislature. English criminal law and the criminal law of some Commonwealth countries and American states recognize offences that were developed entirely by the courts, with no specific basis in statute. Judges built these crimes case by case over centuries, extending liability through analogy to earlier rulings rather than through a legislature setting out the elements of the offence in advance. Because the boundaries of a common law offence depend on how courts have applied and extended it, critics have called such offences unacceptably vague and open to further development by the courts, unlike a statutory offence whose wording fixes what conduct is criminal. Many jurisdictions have moved away from this approach: Canada, most Australian states and New Zealand have abolished common law offences outright, replacing them with codified statutes. England and Wales retains a small number of common law offences but has worked to replace them, where appropriate, with offences precisely defined by statute, reflecting a broader preference in modern legal systems for codified, predictable criminal law over judge made categories of crime.