Here's the scoop on where you can gamble when you're as young as 18, that would allow year-olds to gamble, it was adjourned sine die casinos in Southern California have regulations that allow gambling for. Casino Directory List of all casinos allowing 18 year old + to gamble Most of them have set their age requirement to 21, however several (more than 20!) still allow 18 year olds to play. Also - if you do notice an error, please let us know. All of these only have California legal gambling ages of Poker also has the 18 year old gambling requirement in most cases, though you may find that some.