Asian roulette is where you hook up with an Asian girl, then find out later whether you committed a crime.
It is a well-documented, scientific fact that Asian females of the human race look the same from age 16-50. Google "Average asian aging process" for relevant periodicals
In a bar with a lot of Asian girls of unverified age: "Who's up for some Asian roulette?"
Person A: "Whoa that Asian girl is hot"
Person B: "Only problem is its impossible to tell if Asians are 18 or not"
Person A: "Asian roulette!"