When you place a bet in Roulette, you are essentially wagering on the number that will come up on the spinning wheel. If you are right, you will win your bet, and if you are wrong, you will lose your bet.
What happens to the money that you wagered when the number that comes up is in fact the number that you predicted? If it is a winning bet, then the casino pays you out immediately – usually in cash. However, if it is a losing bet, then the casino keeps your money.
The reason for this is pretty simple. If you lose your bet, then the casino can’t give you anything back – they have already lost the money that you wagered! So, in order to make sure that everyone who plays Roulette (both winners and losers) gets their fair share of money, the casino keeps all of the money that is wagered on every single Roulette bet.
