With the exception of the Wheel of Fortune, there is no casino table game which is easier to play than roulette. You don't have to make any decisions, as in blackjack, nor learn any complicated rules of betting, as in craps.
You simply put your chips on what you want to bet and then wait for the wheel, ball, and croupier to tell you if you have won or lost.
You do have a number of different ways to bet. You can choose to bet one one particular number. If it hits, you get paid 36-1. You can put your chip on the line between two numbers, and if either of them hit you get paid 18-1. You can place it at the junction of 4 different numbers and if any one of those 4 hit you get paid 9-1.
Or, you can take more conservative bets. You can bet on a row of 12 numbers, and get paid 3-1 if you win. You can also select an even-money bet, such as red or black, or high or low.
All of the payouts are based on there being 36 numbers, divided by two colors, on the wheel. If, indeed, that were the case then over the long run both the players and the casino would break even. (Actually, the casino would wind up losing money as it has overhead expenses -- salaries, electricity, etc.) Needless to say, Las Vegas was not built on casinos losing money or even breaking even.
The kicker in all of this are zeroes. They are neither red nor black, odd nor even, high or low. They are not in the high third, the middle third, or the low third. If you bet on any of these, or selected a number from 1 to 36, and a zero hits you lose and so does everyone else at the table who made one of these bets. Zeroes are green and in most European casinos there is only one on the wheel. In America, there are usually 2 - zero and double zero.
The only way to win if a zero hits is to bet on it. You will be paid 36-1, the same as with any other number, and the casino will pay it out happily knowing that it has collected from everyone who took one of the more usual bets.
Are there any other rules? Only two.
Shortly after the croupier starts the wheel spinning he will announce "No more bets." The rule here is simple enough -- you can't bet.
Later, after the ball has landed, the croupier will put a marker on the table, collect all the losing bets, and pay off all the winning ones. Until he removes the marker you can not touch your chips.
Simple enough? Of course it is -- and this simplicity has made roulette the second most popular game in casinos worldwide, beaten only by the slots.