Read this first
Roulette is a game of chance with a built-in house edge. No strategy, system, pattern or timing changes the odds in the player’s favor over time, and most players lose money over time. Nobody should gamble money they cannot afford to lose. The rules described here lower the cost of certain bets, but they do not remove it, and they do not turn roulette into a game that can be beaten. Anyone struggling with gambling can contact a local support service.
The problem these rules address
On a single-zero wheel with 37 pockets, a bet on red wins in 18 pockets and loses in 19: the 18 black pockets and the green zero. The payout is 1 to 1, so the bet is slightly unfavorable to the player. The zero is the only reason for that. Without it, the chances would be level.
Partial-return rules soften the effect of the zero on bets that pay even money: red or black, odd or even, and low or high. Rules differ between places, and a table may offer one, the other, or neither. The posted table rules are the place to check.
Surrender
Under a surrender rule, when the ball lands in zero, the player loses half of an even-money stake and gets the other half back. Anything else is paid or lost as usual.
A hypothetical example with a stake of 10 units on red, single-zero wheel:
- Red lands, 18 pockets out of 37: win 10 units.
- Black lands, 18 pockets out of 37: lose 10 units.
- Zero lands, 1 pocket out of 37: lose 5 units (half is returned).
The average result per spin is (18 × 10 − 18 × 10 − 1 × 5) ÷ 37 = −5 ÷ 37, or about −0.135 units. As a share of the 10-unit stake that is about 1.35 percent, against 10 ÷ 37 = 0.27 units, or 2.70 percent, with no partial return. So surrender cuts the edge on those bets roughly in half.
En prison
Under en prison, a zero does not immediately lose the stake. The stake is “imprisoned,” often marked by the dealer, and stays on the layout for the next spin. If the even-money bet then wins on that next spin, the stake is released and returned to the player with no winnings. If it loses, it is taken. In common versions, if zero comes up again the stake stays in prison for another round, though rules about repeated zeros differ.
With the repeating version on a single-zero wheel, the math works out like this. Let L be the expected loss, as a fraction of the stake, from a stake that is already in prison. On the next spin, 18 of 37 pockets release it (loss of 0), 18 of 37 take it (loss of 1), and 1 of 37 sends it back to prison:
L = 18/37 + L/37
Multiply both sides by 37: 37L = 18 + L, so 36L = 18 and L = 0.5. A stake in prison is therefore worth, on average, half of its value lost, which matches the surrender result. The edge on even-money bets is then 0.5 ÷ 37 = 1/74, again about 1.35 percent. If the rules treat a second zero as a simple loss instead, the figure is a little higher: (1/37) × (19/37) ≈ 0.0139, or about 1.39 percent, since the stake is then lost on 19 of 37 outcomes of the second spin.
En prison and surrender usually reach similar average costs. The difference is how they feel: surrender settles the matter at once, while en prison keeps the bet alive for one more spin.
What these rules do not change
Several limits are worth noting.
- They apply only to even-money outside bets. Bets on a single number, a dozen, a column or any inside bets are unaffected.
- The edge is reduced, not removed. At about 1.35 percent, it is still a negative expected value, and the long-run result is still a loss on average.
- Because the bet still loses on average, the law of large numbers means a long session drifts toward that average. A shorter session can be much better or much worse.
- A lower edge does not mean fewer losses if the player simply plays more, bets more or plays faster. The total cost depends on the amount wagered, which is what hourly expected loss captures.
Why rules vary by table
Rules of this kind are set by the operator and by the local rules that govern the table, so the same game can appear in several versions. Some formats apply the partial return only to certain bets, only on certain wheels, or only up to a stake size. Where the wheel has two zeros, a surrender rule, if offered, may cover both zero pockets. In that case the hypothetical edge on even-money bets with surrender is (2 ÷ 38) × 0.5 = 1/38, about 2.63 percent, compared with 5.26 percent without it. Online and live dealer games may advertise their rules differently from a physical casino floor.
For that reason, rule transparency matters. The posted rules should say plainly whether a zero returns anything, and if the wording is vague the sensible reading is that nothing is returned. Differences like this are exactly the sort of rule variants that change the cost of playing without changing the basic nature of the game.
Putting the figures in perspective
A 1.35 percent edge on a 10-unit bet is an average loss of about 0.135 units per spin. Over 100 spins that is an average loss of roughly 13.5 units (100 × 0.135), while the actual outcome could differ widely in either direction. These numbers are hypothetical illustrations of the average, not predictions of any session. Treating spending as an entertainment budget, and deciding in advance how much is acceptable to lose, is more useful than searching for a favorable rule.