One of the great secrets of roulette is the function of that green zero (and green double-zero in the US) that seems so out of place on the trusty old roulette wheel. 

The reason why it’s there, very simply, is to give the house an advantage over the player. In other words, instead of having a 50% chance of winning if the player bets on odds/ evens or red/ black, they will only have a 48% (or 47% in the US) chance of winning. It’s a small difference over a couple of spins, but it makes a huge difference in the long run.

It also works by completely messing up all bets on the roulette table in the rare instance that the ball lands on it. Here’s how it works:

• If the player bets on 0 or 00 and the ball lands on the 0 or the 00 (obviously, if it lands on one, it can’t land on the other), the player gets a payout of 35 to 1. Which is massive.
  
• If the player does not bet on 0, his or her bet is forfeit – as is every other bet on the table that isn’t bet on a zero. This includes, but is not limited to all outside and inside bets like:

• • Odds and evens bets
  • Red or black bets
  • Every individual number bet
  • Bets on rows of numbers
  • Bets on corners
  • Line bets
  • Five number bets
  • Snake bets
  • High or low bets
    

• If the player bets on 0 and/ or 00, as well as on other bets, they win 35 to 1 for what they bet on that 0 or 00. Every other bet is forfeit.

As such, though it’s basically just rotten luck for you if the ball lands on zero or double-zero, it’s absolutely not worth betting a huge amount of money on zero as the chances are so firmly stacked against you. The payout is high, yes, but the risk is arguably too high. A smart move, then, would be to place most of your inside or outside bets as normal and then put down a few dollars on 0 and/ or 00 to act as a high-payout insurance for the rare case that the ball lands on 0 and every single other bet is forfeit.