A new trial or retrial is a recurrence of a court case. Depending on the rules of the jurisdiction, a new trial may occur if:
In some types of cases (for example, if the original trial court was not a court of record) or in some legal systems, if the losing party to a case appeals, then the appellate court itself will hold a new trial, known as a trial de novo.
In the United States, if a defendant is acquitted of a crime, the Fifth Amendment generally prohibits a retrial; thus, with few exceptions, a retrial only can occur if the verdict in the first trial was "guilty", or if there was no verdict. In other legal systems, the rules may be different.