Cal. Civ. Proc. Code § 1141.21
(a)
(1) If the judgment upon the trial de novo is not more favorable in either the amount of damages awarded or the type of relief granted for the party electing the trial de novo than the arbitration award, the court shall order that party to pay the following nonrefundable costs and fees, unless the court finds in writing and upon motion that the imposition of these costs and fees would create such a substantial economic hardship as not to be in the interest of justice: