Mandatory sentencing requires that offenders serve a predefined term for certain crimes, commonly serious and violent offenses. Judges are bound by law; these sentences are produced through the legislature, not the judicial system. They are instituted to expedite the sentencing process and limit the possibility of irregularity of outcomes due to judicial discretion. Mandatory sentences are typically given to people who are convicted of certain serious and/or violent crimes, and require a prison sentence. Mandatory sentencing laws vary across nations; they are more prevalent in common law jurisdictions because civil law jurisdictions usually prescribe minimum and maximum sentences for every type of crime in explicit laws.