Letting kids gambling is a parental choice, but if you think it's teaching your kid a valuable lesson you are dead wrong.
I'm thinking more about games like roulette, poker, dice with chores money. maybe it would need to be in a more controlled environment, like family game night.
not exactly gambling, but I learned a great lesson from my father this way when I was about eleven or twelve. I really wanted some expensive Lego so I begged my dad to lend money to purchase it. at first he wouldn't do it, but eventually he decided it might be a good learning experience for me. I had a blast playing with that set for a month or two, but after a while it was just one more toy that I owned. it took a lot longer than that to pay him back, so I had ample time to reflect on how much it sucked to be in debt. I never asked my dad for another toy loan, and I've basically never considered borrowing money again for anything other than college.