In most large casinos, you'll find blackjack available in 1, 4, and 8-deck varieties. Sometimes you'll find 2-deck and 6-deck games, but they're less common. 1-deck tables usually shuffle by hand. 4-deck tables and up usually shuffle by machine.

Six-deck and eight-deck blackjack are the most common configurations seen on the casino floor today. You guessed it  these variants use six and eight standard decks, amounting to 312 and 416 cards, respectively. The increased number of decks further tilts the odds to benefit the house.