There are casinos in Southern California that allow 18+ yr. olds to play, but r they limited to certain games?

...or are 18 year olds allowed to do the same things as any 21 year old? I'm thinking of the game No Limit Texas Hold'em Poker primarily, because I think in the past, 18 year olds couldn't play that, but that was long ago, so I don't know if it's still like that today or changed. Thank you.