European roulette is the most common form of the game, both in physical casinos and online. It is the best version in terms of chances because it has a minuscule house edge of only 1.35%. It also features a rule called la partage or en prison, which allows players to get back half of their even money bets if the ball lands on zero.
There are a lot of stories about the origins of roulette. Some fanciful ones include the game being invented by a monk or a French mathematician. Others say it was a Chinese game that was brought to France by Dominican monks, or that it was derived from the older games hoca and portique. The most likely story is that the game evolved in the 17th century in France, where it became popular amongst the aristocracy and soon made its way into the gilded gambling parlours of pre-revolutionary Paris.
There is some evidence that Roman soldiers played a game similar to modern-day roulette. The game involved spinning shields that had symbols on them, and players placed bets based on which symbol they thought would stop closest to an arrow.