Roulette

Roulette is a casino game, in which players may choose to place bets on either a single number or a range of numbers, the colors red or black, or whether the number is odd or even. In Fallout: New Vegas, playing 10 spins of roulette gives you the Little Wheel achievement/trophy.

Gameplay (Fallout: New Vegas)
In the Mojave Wasteland, several casinos run at least one Roulette table, at which the player may win (or lose) a significant amount of money betting on a wide range of outcomes, or one very narrow outcome. To determine the winning number, the Croupier spins the roulette wheel in one direction, and spins a ball in the opposite direction, along a grooved track running the circumfrence of the wheel. When the ball loses momentum and falls into one of the 38 'baskets', the winning number and color is announced, and bets are paid out as appropriate.

The 'house edge' or the 'expected value' is the amount a player is expected to lose, relative to the amount they bet. For American Roulette, the standard played in the Mojave Desert, (numbers 0 to 36, plus 00) the player can expect to lose 5.26% of the chips they bet.

Betting
Betting in Roulette is somewhat more complex than other casino games found throughout the wastes, and is the only real element of strategy involved in the game, since the payout and odds of winning depend on what the player is betting. Bets are divided into two broad categories, based on their likelihood and payout.

Inside Bets
Inside bets are bets that, while having a statistically lower chance of winning, have a much better payout. Inside Bets include:
 * Zero and Double-Zero: 0 or 00; must be bet on individually, as these do not count as Odd, Even, Red or Black.
 * Straight-Up: A single number on the roulette wheel.
 * Split: Any two adjoining numbers on the betting table, either vertically or horizontally.
 * Street: Three adjacent numbers in a row on the betting table.
 * Corner: Also known as a square, a corner is a bet on four adjacent numbers in a two-by-two 'box' on the betting table.
 * Top Line: 0, 00, 1, 2, and 3. The only 'called bet' that includes 0 and 00.
 * The Basket: Either 1, 2, and 0, or 2, 3, and 00.
 * Six Line: Any six numbers from two adjoining rows. (e.g. 1, 2, 3, 4, 5, 6)

Outside Bets
Outside bets are statistically 'safer', being more likely to occur than an inside bet (as low as 1.11-to-1 odds!) but have much lower payouts in return. Ouside Bets include:
 * Red or Black: A bet on whether the winning number will be Red or Black.
 * Odds or Evens: A bet on whether the winning number will be Odd or Even.
 * Dozen: Either the First (1-12), Second (13-24), or Third (25-36) dozen numbers on the wheel.
 * Column: A bet on either the first, second, or third vertical row of numbers.
 * 1-18: A bet on any number in the first half of the 36.
 * 19-36: Same as 1-18, but on the second half of the 36.

Appearances
Roulette can be played in Fallout, Fallout 2 and Fallout: New Vegas. In the first two games, it's played simply through dialogue, while in New Vegas, it's featured as a minigame.