The Martingale is the best-known roulette betting system. It varies greatly. You should follow such principle: if you win, then pocket your bet. If you lose, you should double your previous bet.If you win that will guarantee you get back your previous loss and one more unit.And so on.
The Martingale System works great only in case you have an infinite bankroll and no betting limits.
The d'Alembert system is also rather popular. The system is based on the assumption that after a win you are less likely to win again.So after a win, you subtract a chip from your bet. The d'Alembert system also assumes that you are less likely to lose after a losing spin, so in that case, you add a chip to your bet. The fact that the roulette wheel has no memory and each spin is an independent trial with exactly the same odds of a win or loss is the previous spin is a weak point of the system.

To win is the aim of roulette.The main rule of any sane player consists in calculating his odds and possibilities.The game of roulette is a kind of business.We invest money and expect to get gain.Even though we cannot exclude loss we hope to win. We hope to win despite we cannot exclude loss

Among all the casino games roulette is classic. In any full service casino in the United States besides blackjack and craps you'll find roulette which is more popular in France where it is historically a cultural part of the gambling scene. Roulette was popular in Europe since the 18th century and today it is played online all over the world.Roulette was played in Paris since 1796 and nowadays it almost has't changed. Multiple games gave birth to roulette. To make a modern roulette game an Italian ball game called "biribi" and another wheel game that involved colors but not numbers were combined. The English game "Roly-poly" which consisted of black and white slots was launched in 1720. Thus, roulette is a hybrid of both birib and Roly-poly.To understand a game is to enjoy it.Only in case you understand game you can enjoy it. And it's the amount of pleasure you take away from the tables but not your odds will increase due to the knowledge of the game.

One subject that always comes up when people discuss winning at roulette or getting an edge is the topic of biased roulette wheels. To really find a bias in a wheel, you'd need to clock at least 4000 spins and realistically speaking, you won't find a bias towards red or black. At best you'll find a bias toward a specific set of numbers.
Casinos don't want a biased wheel, because the house edge at roulette relies on the odds being 37 to 1 for each number over time. If certain individual numbers pay out more often than they should, the casino loses money. In this respect, a biased wheel isn't like a fixed game of blackjack. Casinos don't really have an interest in fixing any of their games since the house edge is in their favor on all of them. If you are able to find a biased wheel, you should bet individual numbers as much as you can. If you're in a rare situation where you have an advantage over the casino, you don't want to waste it on bets with low payouts.
Something related to wheel bias dealer signature. Some roulette dealers have been spinning the ball for so long that they do it in exactly the same manner. This produces a situation where some numbers might come up more often than other numbers.
Usually if you're looking for this type of advantage play it's best to find an older dealer who looks really bored. You don't want someone who's really young and just learning how to spin the wheel. You want someone who's spun it so many times that it's become automatic and predictable.
Since it would take about 4000 spins to determine with any degree of certainty any patterns on a roulette wheel, it would take a considerable amount of time to track that many spins. Realistically speaking, you might be better off learning to count cards or play poker really well instead of trying to get an advantage finding a biased wheel or a dealer with a signature.

In some casinos there exist some special rules.
In Prison/En prison
When the ball falls on zero, red/black, odd/even and first half/last half bets will not be collected by the croupier - instead they will have to stay on the table - in other words they are in prison. The players can win their original bet back during the next spin;if their bet wins they get their original bets back without additional gain. If the ball should land on zero once again the bets will remain in prison one more spin and so on. As this special rule reduced the casinos edge, it's greatly to the advantage for the players.
La Partage
In case the ball stops at zero slot, the croupier will not fully collect red/black, odd/even and first half/last half bets. Only half of the players’ bets will be collected - the rest will be returned to the players. As well as the In Prison rule, the La Partage rule also reduces the casinos edge to only 1.35 percent.

A well-known betting system in roulette is the Martingale system. There are a lot of variations of it. The main idea of the system is that when you win, you pocket your bet. If you lose, you should double your previous bet.By doing this in case you win, you get back your previous loss and one more unit.And so on.
The Martingale System works great only in case you have an infinite bankroll and no betting limits.