There are two variations of USA blackjack that are played in US casinos. There is Spanish 21, which is owned by a Colorado gaming publishing company. This form of the game is also known as Spanish Blackjack (although this is the unlicensed version of the game). The other variation of USA blackjack is called 21st century blackjack and it is otherwise known as "Vegas style" blackjack. It is, in fact, commonly found in US gambling rooms in California.

Click here to visit The Best Online Casino

Spanish 21 is a more liberal variation of USA blackjack. Players can double down any number of cards in their hand after splitting Aces. (Some US casinos no longer allow this option.) It is possible to rescue or surrender a bet to the house after doubling. This is known as "double down rescue" and means that the player will forfeit an amount equivalent to his initial wager.

Spanish 21 provides payout bonus for hands that reach 21 with five or more cards. It pays out 3:2 for a five-card 21, 2:1 for a six-card 21 and 3:1 for a seven-card or more 21. (Bonuses are not paid, however, if the player doubled.) It also pays out a bonus payment of 3:2 for 6-7-8 21s and 7-7-7 of mixed suit 21s and 2:1 for those combinations with the same suits. These combinations in spades, pays out 3:1. The biggest bonus payout occurs if a player holds a 7-7-7 and the dealer has a 7 face-up in his cards. This pays $1000 for a $5-$24 bet and $5000 for a $25 or more bet. Other players also win a $50 bonus in this scenario, which is named an "envy bonus."

Player blackjacks or 21s always win in Spanish 21. That is, if a player has blackjack and the dealer also has blackjack, the player wins. All cards with a face value of 10 are removed from the pack (although Jacks, Queens and Kings are left in it). Therefore, Spanish 21 is played a 48-card deck.

The biggest difference of 21st century blackjack in US casinos is that while a player aims for 21, if he goes over, he is not automatically bust. The origins of the game are very interesting. California law prohibited the playing of the game "21", which was ruled to be the game of blackjack, as played in Las Vegas, USA casinos. Therefore, the game of 21st century no-bust blackjack was created, which is just different enough to traditional blackjack to be legal. If a player goes bust, he can push if the dealer goes bust as well, if the dealer busts with a higher total card value than the player.

In this variation of USA blackjack, jokers are used as wild cards – they have any value that the player needs to reach the total of 21. In 21st century blackjack, the house has a 0.6% edge over the players. US casinos that offer 21st century blackjack (typically card rooms found in California) charge a collection fee per hand played. This generally works out to 1% of the total money played.