Zero is the green roulette pocket marked 0. It is not red, black, odd, even, high, or low for normal outside bets. Zero is the main reason roulette has a house edge even when a bet seems to cover almost half the wheel.
Plain Talk
If roulette had only 36 numbers and paid fair odds, many common bets would be much closer to fair. Zero changes that. It adds a result that usually belongs to the house.
On European roulette, there is one zero. On American roulette, there is zero and double zero.
| Term | Plain-English meaning | Where it appears | Why it matters |
|---|---|---|---|
| Zero | Green 0 pocket | Wheel and layout | Creates the standard house edge |
| Straight-up zero | Bet directly on 0 | Inside betting area | Pays like any single number |
| Zero on outside bets | Losing result for red/black, odd/even, high/low | Outside bets | Breaks the 50/50 illusion |
| La Partage / En Prison | Special rules on some French tables | Even-money bets | Can reduce zero damage |
Where You See It
Zero appears on the roulette wheel and betting layout. On European roulette, it is the only green pocket. On American roulette, it sits with double zero.
Why It Matters
Zero matters because it explains the entire roulette business model in one pocket. Players can win any individual spin. The casino wins the pricing of the game over volume.
When zero lands, most outside bets lose. A straight-up bet on zero can win, but that does not remove the house edge because the payout is still below true odds.
Example
On a European wheel, a $10 red bet covers 18 numbers. There are 18 black numbers and one zero.
If zero lands, the red bet loses. So does a black bet, odd bet, even bet, high bet, and low bet.
From the Casino Side:
From the casino side, zero is not a side detail. It is the built-in margin. It lets the table offer simple 1:1 bets that look almost fair while still producing a long-run edge.
Operations teams also care about zero because rule variations such as La Partage and En Prison change expected hold on even-money bets.
Common Misunderstanding
The common misunderstanding is thinking zero is just another number. It is a number for straight-up betting, but it is not part of the outside categories most beginners use.
Another mistake is assuming a zero spin means another zero is unlikely next. Each spin is independent.
Hard Truth
Hard Truth: The zero pocket is small on the layout, but it is the reason the table exists.
Related Terms
FAQ
Is zero red or black?
No. Zero is green.
Is zero odd or even?
For roulette betting, zero is neither odd nor even.
Can I bet on zero?
Yes. A straight-up bet on zero is allowed on standard roulette layouts and usually pays 35:1.
Why does zero give the casino an edge?
Because many bets pay as if the wheel were evenly split, but zero adds an extra losing result.
Is single-zero roulette better than double-zero roulette?
Yes. Single-zero roulette usually has a lower house edge than double-zero roulette.
Deeper Insight
Zero teaches a core casino lesson: the house edge often comes from a small rule that looks harmless. One extra result can turn a near-even bet into a negative-expectation bet.
For a wider view, read House Edge, Expected Value, and Roulette.
Formula / Calculation
| Wheel | Total pockets | Zero pockets | Standard straight-up payout | Standard house edge |
|---|---|---|---|---|
| European roulette | 37 | 1 | 35:1 | About 2.70% |
| American roulette | 38 | 2 | 35:1 | About 5.26% |
House Edge on European straight-up = 1 - (36 / 37) = 1 / 37
Formula Explanation in Plain English
A winning single-number roulette bet returns 35 units of profit plus the original stake. Fair odds on a 37-pocket wheel would require a better deal than that. The missing piece is the casino edge.
Related Reading
Read European Roulette to see the single-zero version and American Roulette to see how double zero changes the game. For special zero rules, continue with La Partage and En Prison. The Glossary connects this term to broader casino math and rules. Safer-play reminders are available from the UK Gambling Commission.