Civil law (common law)
Bench trials have several advantages. They are usually much less formal than a jury trial. Attorneys for both sides can usually agree on the facts of a case before the trial starts. This can save a great deal of time otherwise spent on hearing witnesses and reviewing evidence. This can save on the costs of a trial. In a jury trial, the judge is required to give instructions to the jury before they deliberate. If a judge makes an error in his instructions, this is called a reversible error and can be used as a basis for an appeal. In a bench trial, the judge gives no instructions since there is no jury. This means the judge cannot be reversed due to an error in the instructions.