The Zero Is Why These Bets Exist
You sit down at a roulette table and the felt offers more than just numbers. It offers pairs of outcomes: red or black, even or odd, low or high. None of those pairs covers the zero. That gap is not an oversight in the game's design; it is the entire reason the pairs are there. A bet on red or black, or on even or odd, gives you a wager that feels close to a coin flip while the wheel quietly keeps a pocket that belongs to the house.
On a European wheel with 37 pockets, the numbers 1 through 36 split evenly into 18 red and 18 black, 18 even and 18 odd. The single zero is neither red nor black in the sense that matters for the bet, and it is not counted as even. On an American wheel with 38 pockets, the same is true, and the double zero adds a second pocket that sits outside both pairs. That is why these bets pay even money, or 1 to 1: the payout matches the stake, but the chance of winning is slightly less than half because of the zero or zeros. The house edge on these bets comes entirely from the pocket or pockets that make the bet lose.
What Even/Odd and Red/Black Cover
These are called even-money bets, or sometimes outside bets because they sit on the outer part of the layout rather than on the numbered grid. A red/black bet wins if the ball lands on any pocket of the chosen colour. An even/odd bet wins if the ball lands on any even or odd number, depending on your choice. The zero and, on an American wheel, the double zero are losing results for all of these bets under the standard rules.
Some tables apply a rule that changes what happens when the zero appears on an even-money bet. Under that rule, known in different places by different names, the stake is not taken immediately. Instead it is held, or "imprisoned," for the next spin, and it is returned if the next spin wins, or lost if the next spin loses. Other tables simply take the stake when the zero lands. The rule in force changes the house edge on these bets, so it is worth checking the table's posted rules before you play. A table that imprisons the stake on zero gives a lower edge on even-money bets than a table that takes it outright, all else being equal.
How a Round Plays Out
A round of roulette moves quickly, and the even-money bets are the simplest part of it. You buy in at the table and receive chips. The dealer announces that bets are open. You place your wager on the red or black diamond, or on the even or odd box, or on any combination of outside and inside bets. The dealer spins the wheel and launches the ball in the opposite direction. When the ball drops into a pocket, the dealer marks the winning number and settles every bet on the layout. Winning even-money bets are paid at 1 to 1, meaning you receive your stake back plus an equal amount. Losing bets are collected.
Because the even-money bets sit on the outside of the layout, they are easy to reach and easy to read. That makes them a common first bet for a new player, and they also tend to have the lowest minimum and the highest maximum of any wager on the table. The table minimum applies to each individual outside bet, so a minimum bet on red and a minimum bet on odd costs twice the minimum if you play both at once.
Comparing the Main Roulette Bets
Roulette offers a range of bets, and they do not all carry the same house edge. The even-money bets are among the better choices on the table, but they are not the only ones, and the difference between a European and an American wheel changes the maths for every bet on the layout.
| Bet type | What it covers | Payout | What changes the edge |
|---|---|---|---|
| Red/black | 18 pockets of one colour | 1 to 1 | Zero and double zero lose; imprisonment rule may apply |
| Even/odd | 18 even or 18 odd numbers | 1 to 1 | Zero and double zero lose; imprisonment rule may apply |
| Low/high | 1-18 or 19-36 | 1 to 1 | Same zero exposure as red/black and even/odd |
| Single number | One pocket | 35 to 1 | Payout is below the true odds of 36 to 1 on a European wheel |
| Two numbers (split) | Two adjacent pockets | 17 to 1 | Same structural shortfall as a single number |
| Three numbers (street) | A row of three | 11 to 1 | Same structural shortfall scaled to three pockets |
| Six numbers (line) | Two adjacent rows | 5 to 1 | Same structural shortfall scaled to six pockets |
The key comparison is between the European and American layouts. A European wheel has 37 pockets and a single zero. An American wheel has 38 pockets and adds a double zero. The extra pocket increases the house edge on every bet, including the even-money bets, because it adds one more losing result without changing the payout. On a European wheel, an even-money bet loses on one pocket out of 37. On an American wheel, the same bet loses on two pockets out of 38. The American layout is therefore the more expensive version of the same game for the player, all else being equal.
What the Even-Money Bets Do Not Do
A common misreading is that red/black and even/odd are somehow fair bets because they pay even money. They are not. The payout is even, but the chance of winning is below half, and the gap between the payout and the true odds is the house edge. Another misreading is that a run of reds makes black more likely on the next spin. The wheel has no memory. Each spin is an independent event, and the probability of red or black on the next spin is the same as it was on the previous one, zero included. No sequence of past results changes the built-in edge on an even-money bet.
These bets also do not become better or worse depending on how you size them. A larger stake on red does not change the edge; it changes the amount of money exposed to that edge per spin. The only structural choices that change the edge on an even-money bet are the wheel type and the zero rule in force at the table. Everything else is variance: short-run swings around a long-run average that always favours the house.
Procedural Mistakes New Players Make
The first mistake is betting before the dealer has opened the betting window. Roulette tables run on a strict sequence, and a chip placed while the ball is already in motion or after the call of "no more bets" will be returned or, at some tables, treated as void. Watch the dealer's signal and place your wager only when bets are open.
The second mistake is mixing up the even-money bets with the inside bets when reading the payout. A bet on a single number pays 35 to 1, but a bet on red pays 1 to 1. New players sometimes expect a colour bet to pay more because it covers 18 numbers, but the payout is low precisely because the coverage is broad. The payout is printed on the layout, and it is worth reading before the ball lands, not after.
The third mistake is assuming that the zero is covered by an even-money bet. It is not, and on an American wheel neither is the double zero. If you want to cover the zero, you must place a separate bet on it, and that bet carries its own, higher house edge. Playing an even-money bet and a zero bet together does not cancel the edges; it adds a second wager with a worse rate of loss to the same spin.
Why These Bets Remain Popular
Even-money bets are popular because they are easy to understand, they resolve on every spin, and they produce frequent wins and losses in a steady rhythm. A player who bets red will win on just under half of all spins on a European wheel, which means the session feels active and the stake lasts longer in terms of decisions per unit wagered than it would on a single-number bet. That is a statement about the pace of play and the distribution of outcomes, not about profitability. The expected loss per unit wagered is lower on an even-money bet than on most inside bets, but it is still a loss in expectation, and it is higher on an American wheel than on a European one.
If the table offers the imprisonment rule on even-money bets, that rule reduces the expected loss on those specific bets. It does not change the odds of the next spin, and it does not make the bet positive for the player. It simply returns part of the stake on some zero outcomes instead of taking all of it. The rule is a table-level condition, and it is one of the few things a player can check before sitting down that genuinely changes the cost of the even-money bets.
FAQ
Is red or black more likely than even or odd?
No. On a standard wheel, red and black each cover 18 pockets, and even and odd each cover 18 pockets. The probability of winning is the same for all four bets on the same wheel, and the zero or zeros are losing results for all of them. The only difference is the label on the bet, not the chance behind it.
Does the zero count as even on some tables?
No. The zero is not an even number, and it is not covered by an even-money bet under standard roulette rules. On tables with an imprisonment rule, a zero spin may hold the stake for the next spin rather than taking it immediately, but the zero itself is still a losing result for red/black, even/odd, and low/high bets.
Why does an American wheel make these bets worse?
An American wheel adds a double zero, which is a second pocket that loses for every even-money bet. The payout stays at 1 to 1, but the chance of winning drops because there is one more losing pocket on the wheel. That extra pocket increases the house edge on all bets, including red/black and even/odd.
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