Blackjack

Blackjack is a card game in Fallout: New Vegas, playable in any of the six working casinos. Playing 10 hands of Blackjack grants the Courier the Double Down achievement/trophy.

Rules
All casinos in New Vegas use the following rules.
 * The game is dealt from multiple decks, which are shuffled after every hand.
 * The player character may not purchase insurance.
 * Early surrender (i.e., before checking for dealer blackjack) is not offered.
 * Blackjack payouts and surrendered bets are rounded up.
 * The player character can double down on any starting hand.
 * The player character may only split into two hands.
 * The player character may only split identical card values (that is, the player character may not split Queen-King).
 * A card is dealt with the second hand of a split before the player character is allowed to act on the first.
 * The player character may only double the first of two split hands.
 * The player character may draw to the second of two split hands before drawing to the first.
 * The possible bets are 1-10, 15, 20, 25, 30, 35, 40, 50, 60, 70, 80, 90, 100, 125, 150, 175 and 200.

House rules

 * Each casino has its own rules regarding blackjack payouts and when the dealer must draw. The rules can be seen on the table felts in each casino floor.
 * Barring variations from Luck, the best odds are found at The Tops, Ultra-Luxe or Sierra Madre Casino & Resort. The worst odds are found at the Atomic Wrangler, thanks to the low blackjack payout.
 * Blackjack payout: A blackjack is a hand that is an ace and a 10-point card (it is special since it is a 21 with only two cards). If the dealer gets a blackjack, the player character's second card will be revealed to determine if the player character also has a blackjack. If not, the player character instantly loses, without any opportunity to play.
 * If the player character gets a blackjack and the dealer does not, they instantly win and receive a bonus payout based on the casino. A blackjack payout of 3 to 2 means the player character receives 3 chips for 2 chips they wagered. If both the dealer and the player character get blackjack, it is a push and the player character keeps their bet.
 * Given neutral Luck (6 or less), a blackjack will occur between 0.3-5% of the time. A reduced blackjack payout strongly favors the casino.
 * Dealer must draw to 16, and stand on all 17s: No matter what, if the dealer has a total of less than 17, they continue to hit. If the dealer has a total of 17 or higher, the dealer stays.
 * Dealer must hit soft 17: A "soft" hand is a hand that involves an ace since an ace can be either 1 or 11. A soft 17 is any hand where the ace is used as an 11 since there is still a choice on what the ace can be. This is in contrast to a "hard" 17 that uses an ace, such as Jack-4-2-Ace. In this case, the ace has to be a 1 in order to prevent a bust. Under this rule then, the dealer normally stays on 17, unless that 17 was made initially by an ace being used as 11, at which point the dealer hits again.
 * On the one hand, this can be seen as increasing the chance of a bust, but because the ace can be used as a 1 or 11, if the dealer draws a high card, the initial ace can be used as a 1 instead. Especially since the dealer does not need to play at all if the player character busts, the net result of this rule is that the odds increase in favor of the casino. For this reason, Gomorrah and Primm rank below the Strip casinos in terms of equal odds.

Playing to win
As in real life, Blackjack is the closest to being "fair" a casino game can get. That being said, with neutral luck, even with optimal, standard strategy (see wikipedia's entry on strategy which includes a table on when to stay, hit, double-down and surrender), the odds still favor the house by a margin of a percent or so (though worse at Gomorrah and Primm, even more so at Atomic Wrangler). Essentially, each game becomes a coin flip.

Starting with a Luck of 7, the odds shift in the player character's favor given optimal play. With a Luck of 8, a player character can play suboptimally (not surrendering or doubling down on certain hands, for example) and still pull ahead. With a Luck of 10, the player character pretty much has to try to intentionally lose in order to not make scad of caps from Blackjack. This influence of above-average Luck means that optimal strategy in a New Vegas casino can be very different than what an experienced Blackjack player may have learned. In particular, the tendency not to bust when a character has a high Luck value makes doubling down effective in many more situations and removes the incentive to surrender when dealt with what would otherwise be a weak hand.

With a low level of Luck, the game will be strongly rigged against the player character. The dealer will get blackjacks far more often than normal, and the statement "You feel unlucky" will appear whenever the game has rigged the hand against them. Playing to win without a high luck level is suicide unless one resorts to save-scumming, which the point below addresses.

If one tries to cheat the system by loading after a loss, the dealer will take a minute to 'change out the deck' before they can continue playing.

Appearances
Blackjack can only be played in Fallout: New Vegas.

Behind the scenes
James Garcia created the 3D model for the blackjack table.

Bugs
The dealer will hit any 17 containing an ace on tables where they must hit soft 17, even if it is not a soft 17 (for example a king, a six and an ace).