A game of roulette usually contains a total of 38 chips, with 18 black chips, 18 red chips, and 2 green chips. However, the number of chips can vary depending on the house rules. For example, some casinos may use only 16 chips (8 black, 8 red), while others may use as many as 50 chips (20 black, 20 red, and 10 green).
The number of players also affects the number of chips needed. A game with 10 players would require a minimum of 40 chips (20 black, 20 red), while a game with only 2 players would only need 22 chips (11 black, 11 red).
The house edge in roulette comes from the fact that there are more ways to lose a bet than to win one. For example, there are 36 numbers on the wheel but only 18 ways to win a bet (1-18, 19-36, 1-12, 13-24, 25-36, evens, odds, reds, blacks, 1st dozen, 2nd dozen, 3rd dozen).
This gives the casino a 2.7% edge over the player.
The number of chips needed for each player depends on the house rules and the number of players at the table. However, in most cases, each player will need at least 38 chips to play roulette.