No one exactly knows how the game was invented, but it was probably a mixture of a couple of English wheel games - Roly-Poly and Ace of Hearts - and a few Italian board games.
Right between England and Italy we find France, which already had a board game named Roulette, and that's where the fusion took place.
Early American roulette game (Image credit: Wikipedia)
Roulette Can't Be Canadian, Can it?
The French novel "La Roulette, on le Jour" from 1796 describes a Roulette wheel in Paris, so we can know for sure that the game was played, in its current form, in the late 18th century.
Strangely enough there are even earlier references to roulette on the other side of the pond. In 1758, French Quebec published a regulation that banned four different games: dice, hoca, faro and roulette.
With that in mind, it's quite probable that the game was played before 1750 in Europe. Or maybe the Canadians invented roulette, and if so, we have to rewrite history I'm afraid.
Zero Can Gain Profit
When I said that roulette was played in its current form in late 18th, I wasn't telling the whole truth.
In 1842, the Frenchmen Francois and Louis Blanc revolutionized roulette, at least for the casino owners. They decided to add a "0" to the wheel, and suddenly, the house got an edge. When the game crossed the Atlantic (for the second time?) "00" was also added to give the house an even larger advantage.
The Devil's Game
Legend says that Francois Blanc, who also opened the first casino in Monte Carlo, was in contact with Beelzebub himself when designing the modern roulette.
Well, add the numbers on a roulette wheel, from 1 to 36, and you'll get 666, the number of the beast.