For a game like roulette, the online casinos will have a live dealer (or sometimes just a live wheel where the ball gets inserted automatically). All your bets are placed on your phone screen but the wheel spins in real life, and then the result is seamlessly digitized, so you're paid out immediately.
The Best Roulette Strategies
Martingale For beginners and newcomers to the little wheel.
D'Alembert For players with a large bankroll available.
Fibonacci Sequence For experienced roulette players.
Parlay For players who don't like taking big risks.
Double Street Quad For those looking for larger wins.