A judge, or justice, is an official who presides over a court of law. The powers, functions, method of appointment, discipline, and training of judges vary widely across different jurisdictions. The judge is like an umpire in a game and conducts the trial impartially and in an open court. The judge hears all the witnesses and any other evidence presented by the prosecution and the defence. If the accused is convicted, then the judge pronounces the sentence.

Judges in legal system

There are significant differences between the role of a judge in the common law system descended from British practice, and civil law systems descended from continental European judicial practice. The descriptions below are necessarily archetypical. Details vary from judicial system to judicial system. In many cases, the judicial systems have experienced convergent evolution, expressly or unconsciously adopting similar practices or operating in a manner that minimizes the impact of formal differences between the archetypical role of each system's judges.

For example, while common law judicial procedure generally contemplates a single evidentiary trial, many cases are actually resolved through testimony taken from witnesses in isolated depositions prior to trial that support written presentations to a judge. Similarly, while civil law judges must have some statutory point of departure for their legal rulings, there are accepted methods of legal reasoning that often afford them greater latitude to fit the law to the circumstances of an unusual case than a stark statement of the underlying principles of the system would suggest. This can serve a purpose similar to the common law method of legal reasoning known as stare decisis.

Common law legal systems

In common law countries, judges usually operate under the adversarial system of justice. At the trial level a single judge usually presides over court proceedings (there are some narrow exceptions).

Professional background

Common law judges are generally appointed or elected after careers as practicing lawyers, although many receive brief educational programs specific to judging once taking the bench. Judges are frequently drawn from the ranks of barristers, as opposed to solicitors, where a distinction is made between the two as separate legal professions.

Many U.S. states permit non-lawyers to serve as justices of the peace or as inferior jurisdiction judges in rural areas, but this practice is generally limited to less serious criminal offenses and small claims. Federal judges are not required by law to be attorneys, but it has been long established that the President traditionally appoints only attorneys to the federal bench.

Judges and juries

In the common law system, when there is a jury trial in the trial courts, the jury generally decides questions of fact (guilty or not guilty, whether a party was negligent, etc.) while a single judge decides questions of law (under common-law systems, one of the judge's most important powers is to craft jury instructions).