Cal. Pen. Code § 412
Any person, who, within this state, engages in, or instigates, aids, encourages, or does any act to further, a pugilistic contest, or fight, or ring or prize fight, or sparring or boxing exhibition, taking or to take place either within or without this state, between two or more persons, with or without gloves, for any price, reward or compensation, directly or indirectly, or who goes into training preparatory to such pugilistic contest, or fight, or ring or prize fight, or sparring or boxing exhibition, or acts as aider, abettor, backer, umpire, referee, trainer, second, surgeon, or assistant, at such pugilistic contest, or fight, or ring or prize fight, or sparring or boxing exhibition, or who sends or publishes a challenge or acceptance of a challenge, or who knowingly carries or delivers such challenge or acceptance, or who gives or takes or receives any tickets, tokens, prize, money, or thing of value, from any person or persons, for the purpose of seeing or witnessing any such pugilistic contest, or fight, or ring or prize fight, or sparring or boxing exhibition, or who, being the owner, lessee, agent, or occupant of any vessel, building, hotel, room, enclosure or ground, or any part thereof, whether for gain, hire, reward or gratuitously or otherwise, permits the same to be used or occupied for such a pugilistic contest, or fight, or ring or prize fight, or sparring or boxing exhibition, or who lays, makes, offers or accepts, a bet or bets, or wager or wagers, upon the result or any feature of any pugilistic contest, or fight, or ring or prize fight, or sparring or boxing exhibition, or acts as stakeholder of any such bet or bets, or wager or wagers, shall be guilty of a misdemeanor, and upon conviction thereof, shall be fined not less than one hundred dollars nor more than one thousand dollars and be imprisoned in the county jail not less than thirty days nor exceeding one year; provided, however, that amateur boxing exhibitions may be held within this state, of a limited number of rounds, not exceeding four of the duration of three minutes each; the interval between each round shall be one minute, and the contestants weighing one hundred and forty-five pounds or over shall wear gloves of not less than eight ounces each in weight, and contestants weighing under one hundred and forty-five pounds may wear gloves of not less than six ounces each in weight. All gloves used by contestants in such amateur boxing exhibitions shall be so constructed, as that the soft padding between the outside coverings shall be evenly distributed over the back of said gloves and cover the knuckles and back of the hands. And no bandages of any kind shall be used on the hands or arms of the contestants. For the purpose of this statute an amateur boxing exhibition shall be and is hereby defined as one in which no contestant has received or shall receive in any form, directly or indirectly, any money, prize, reward or compensation either for the expenses of training for such contest or for taking part therein, except as herein expressly provided. Nor shall any person appear as contestant in such amateur exhibition who prior thereto has received any compensation or reward in any form for displaying, exercising or giving any example of his skill in or knowledge of athletic exercises, or for rendering services of any kind to any athletic organization or to any person or persons as trainer, coach, instructor or otherwise, or who shall have been employed in any manner professionally by reason of his athletic skill or knowledge; provided, however, that a medal or trophy may be awarded to each contestant in such amateur boxing exhibitions, not to exceed in value the sum of $35.00 each, which such medal or trophy must have engraved thereon the name of the winner and the date of the event; but no portion of any admission fee or fees charged or received for any amateur boxing exhibition shall be paid or given to any contestant in such amateur boxing exhibition, either directly or indirectly, nor shall any gift be given to or received by such contestants for participating in such boxing exhibition, except said medal or trophy. At every amateur boxing exhibition held in this state and permitted by this section of the Penal Code, any sheriff, constable, marshal, policeman or other peace officer of the city, county or other political subdivision, where such exhibition is being held, shall have the right to, and it is hereby declared to be his duty to stop such exhibition, whenever it shall appear to him that the contestants are so unevenly matched or for any other reason, the said contestants have been, or either of them, has been seriously injured or there is danger that said contestants, or either of them, will be seriously injured if such contest continues, and he may call to his assistance in enforcing his order to stop said exhibition, as many peace officers or male citizens of the state as may be necessary for that purpose. Provided, further, that any contestant who shall continue to participate in such exhibition after an order to stop such exhibition shall have been given by such peace officer, or who shall violate any of the regulations herein prescribed, for governing amateur boxing exhibitions, shall be deemed guilty of violating this section of the Penal Code and subject to the punishment herein provided.
Nothing in this section contained shall be construed to prevent any county, city and county, or incorporated city or town from prohibiting, by ordinance, the holding or conducting of any boxing exhibition, or any person from engaging in any such boxing exhibition therein.
Ca. Pen. Code § 412