To calculate the optimal bet size for your bankroll at El Royale Casino, a common rule of thumb is to wager no more than 1-5% of your total bankroll on any single bet. This helps ensure that you don’t risk too much in one go, giving you a better chance of playing for a longer period without depleting your funds. For example, if you have a $200 bankroll, your bet size should range from $2 to $10 per bet.