There are a couple of little known roulette rules which do favour the player if they are betting on outside even money bets. Quite popular in European land casinos, the La Partage rule gives half back if the ball lands on green (0). For example, if I bet £10 on red and 0 comes out, I will get £5 back.
This reduced the house edge to just 1.35%, compared to 2.7% without the rule. Intuitively, you can see how this would be the case. The house edge is created by the zero. If, when the zero comes up, only half the bet is lost, you can see how this would reduce the house edge by half.
You can work it out mathematically too. With the La Partage rule, a bet with £2 either returns, £0, £1 or £4 when bet on the outside. Now imagine, that instead of paying out £1, the casino offers the player a chance to bet the £1 at 3/1 to either get £4 or zero. The outcome could be decided by flipping 2 coins so there is no house edge at all. On average, the player will walk away with £0, 3/4 times and £4, 1/4 times. No odds have changed in the roulette game, it just means that now, a spin on red, can only lead to 2 outcomes, zero or £4.
So over 148 spins, the player will win £4 with a probability of 73/148. If the house edge was zero then the player would would have a 74/148 chance of winning. 1 – (73/74) = 1.35% house edge.
A similar rule which I have not seen anywhere is called En Prison. With that, if the ball lands on green, the stake is imprisoned. The wheel is spun again and if the bet is a winner, then the bet gets returned but no winnings. This roughly has the same effect as La Partage but is ever so slightly worse. Obviously the best way to minimise losses at the roulette table is not to play so its preferable to have La Partage where you get half your money back straight away rather than having to gamble again.
If you want an online casino with La Partage, look for French roulette but be warned not all French roulette tables have this rule. If you want to play at an online casino with La Partage try Roxy Palace Casino. They offer a free £20 no deposit for first time users and a £150 matched bonus. Their Video Roulette table has La Partage. Sign up here