Single-zero wheels are relatively rare in Las Vegas. And even where they exist, they’re often dealt only for high stakes or during restricted hours. Some are opened only upon specific request from high rollers. The casino edge for the standard double-zero game that you find throughout Las Vegas is 5.26%. A single-zero wheel lowers that edge to 2.7%.
The green zeros on a roulette wheel are what give the house its advantage. If there were no zeros, players could wager simultaneously on red and black, break even, and enjoy free cocktails all night long. Add the zeros and this strategy is no longer viable, because when a zero comes up, all bets on the layout (except those on zero) lose. European wheels have only one zero, while the majority of American wheels have two, a fact that has led many a visitor from the Continent to refer to our version as "the classic example of American greed and barbarism."
Following is a list of wheel variations and the resulting casino advantage:
European (even-money bets only), 1.35% -- The low edge results from combining a single-zero-wheel and a rule called "en prison." En prison effectively cuts the loss on the even-money wagers to only half a bet. In his new book Gambling 102, Michael Shackleford discusses minor variations in games he’s seen in Holland (1.37% edge) and Berlin (1.39%). Note that the non-even-money bets have the standard single-zero edge of 2.7%.
Atlantic City double zero (even-money bets only), 2.63% -- Atlantic City has a rule sometimes referred to as "surrender," which evolved from an attempt to implement en prison (customers were confused, so the rule was modified). On double-zero games, even-money wagers lose only half a bet when either of the zeros comes up. The other bets on the table have the traditional 5.26% edge.
Standard single zero, 2.7% -- These games can be found in Atlantic City, Canada, and from time to time in Nevada and other American casinos.
Standard double zero, 5.26% -- The most common game in Las Vegas and most American gambling venues. All bets except the "five-number bet" (which comes in at 7.89% for the house) have the same house edge.
Triple zero, 7.69% -- Triple-zero wheels have been known to show up at charity gambling functions.
Animals, 10%+ -- Rumor has it that during Carnaval in some South American countries, unscrupulous gamesmen pad their edge by adding house numbers to the wheel. They do this by replacing numbers with pictures of animals, which function the same as zeros. Since complete details regarding the substitutions are unknown to us, we can't give an exact percentage. But if one ox and one bull replace one black number and one red one, the house edge leaps to 10.53%.
Stephen King, 18.42% -- A short story by Stephen King titled "Lucky Quarter" mistakenly cites a 30-1 (instead of 35-1) payoff for a single-number wager. The resulting edge is 18.42%. King really is a horror writer.
The accompanying list identifies all the casinos in the Las Vegas area that have single-zero roulette wheels, at least part-time.
