Bus. & Prof. Code, § 19941

(a) A person under 21 years of age shall not do any of the following:

(1) Play, be allowed to play, place wagers at, or collect winnings from, whether personally or through an agent, a gambling game.

(2) Be employed as an employee in a licensed gambling establishment, except as provided in Section 19912.

(3) Present or offer to a licensee, or to an agent of a licensee, written, printed, or photostatic evidence of age and identity that is false, fraudulent, or not actually the person’s own for the purpose of doing any of the things described in paragraphs (1) and (2).

(4) Loiter in or about a room in which a gambling game is operated or conducted.

(b) A licensee or employee in a gambling establishment who knowingly violates or knowingly permits the violation of paragraphs (1) to (3), inclusive, of subdivision (a) is guilty of a misdemeanor.

(c) A person under 21 years of age who violates this section is guilty of a misdemeanor.

(d) Proof that a licensee, or agent or employee of a licensee, demanded, was shown, and acted in reliance upon bona fide evidence of age and identity shall be a defense to any criminal prosecution under this section or to any proceeding for the suspension or revocation of a license or work permit based thereon. For the purposes of this section, “bona fide evidence of age and identity” means a document issued by a federal, state, county, or municipal government, or subdivision or agency thereof, including, but not limited to, a motor vehicle operator’s license or an identification card issued to a member of the Armed Forces, that contains the name, date of birth, description, and picture of the person.