No person under the age of twenty one (21) years shall be allowed to play any licensed game, or slot machine or loiter about any room or premises wherein any game or slot machine provided for in this chapter is operated or conducted, and in any legal action it shall be no excuse for the licensee, employee or dealer operating or conducting a licensed game to plead he believed the party to be twenty one (21) years old or over; and any licensee, employee or dealer operating or conducting any game who shall permit any person under the age of twenty one (21) years to play at such game or games or permit any such person to loiter about the room or premises in which such game or games may be conducted or operated, shall be deemed guilty of a city offense and upon conviction thereof shall be punished as provided in title 1, chapter 3 of this code. (Ord. 290, 8-26-1980)