Amato violated Riverside County’s local rule about filing jointly prepared pretrial statement witness and exhibit lists, and jury instructions the first day of a jury trial or before. As a result, the trial court held that Amato had waived his right to a jury trial, and after hearing his evidence, granted a motion for judgment under CCP 631.8. This decision holds that the trial court erred. The right to a jury trial may be waived only by the methods established by the constitution or statute, neither of which permit a jury trial waiver as a sanction for failure to comply with local court rules on pretrial preparation. Furthermore, the error in denying a jury trial was reversible per se. The Court of Appeal refused to consider whether the trial court might properly have nonsuited plaintiff if a jury trial had been held.