In roulette, the single zero pays out as a black number. Roulette is a casino game that uses a spinning wheel with numbered slots to determine the outcome of a bet. The player bets on one of the numbers on the wheel by placing chips or coins into one of the designated slots. When the wheel stops, the number in the slot corresponding to the bet is revealed.
If that number is black, then the player has won the bet and will receive their original chip or coin plus any additional winnings. If that number is red, then the player has lost the bet and will lose whatever chips or coins they put into that slot.