I think casinos enforce rules and etiquette in roulette games through the supervision of dealers and pit bosses, who monitor the table for proper conduct and adherence to game rules. Security cameras and other surveillance tools help ensure fair play. Clear instructions are given before each game, and any violations, such as late bets or disruptive behavior, are addressed immediately. Players who repeatedly break rules may be warned or removed from the game, maintaining a respectful and orderly atmosphere.