How do civil-law and common-law systems differ in the role judges play during a trial?

The primary difference between civil-law and common-law systems lies in the judge's level of involvement in the trial process, defined largely by whether the procedure is inquisitorial or adversarial.12

Common-Law Systems

Common-law jurisdictions utilize an adversarial system. In this model, the responsibility for gathering and presenting evidence rests primarily with the parties and their attorneys. The judge acts as a neutral arbiter, overseeing the proceedings and ensuring that the presentation of evidence adheres to procedural rules. In cases involving a jury, the judge determines the applicable law while the jury determines the facts. Even in bench trials where the judge decides both law and fact, their role remains largely limited to evaluating the presentations made by the opposing sides.1234

Civil-Law Systems

Civil-law jurisdictions typically employ an inquisitorial system. Here, the judge takes an active, investigative role, acting as a guarantor of a just outcome. Judges are responsible for discovering the facts, which includes questioning witnesses, examining documents, and ordering the collection of evidence. In many civil-law countries, judges are also required to guide the proceedings by directing the parties to focus on specific points of fact or law.123