California Code, Code of Civil Procedure - CCP § 1021.11

(a) Notwithstanding any other law, any person, including an entity, attorney, or law firm, who seeks declaratory or injunctive relief to prevent this state, a political subdivision, a governmental entity or public official in this state, or a person in this state from enforcing any statute, ordinance, rule, regulation, or any other type of law that regulates or restricts firearms, or that represents any litigant seeking that relief, is jointly and severally liable to pay the attorney's fees and costs of the prevailing party.

(b) For purposes of this section, a party is considered a prevailing party if a court does either of the following:

(c) Regardless of whether a prevailing party sought to recover attorney's fees or costs in the underlying action, a prevailing party under this section may bring a civil action to recover attorney's fees and costs against a person, including an entity, attorney, or law firm, that sought declaratory or injunctive relief described by subdivision (a) not later than the third anniversary of the date on which, as applicable:

(d) None of the following are a defense to an action brought under subdivision (c):

(e) Any person, including an entity, attorney, or law firm, who seeks declaratory or injunctive relief as described in subdivision (a), shall not be deemed a prevailing party under this section or any other provision of this chapter.