
3-Card Poker uses two alternating decks. Standard 52-card decks are used in the game, with normal 2 to Ace card rankings, barring the Joker card. The decks always feature the same design but with different back colors.
So, why do Three Card Poker games use two alternating decks?
The answer is tied to automated shuffling machines. While one deck is in play, the other is shuffling in the machine. The two decks are constantly rotated in and out of play. Most casinos change decks for every other round.
Additionally, every couple of rounds, the dealer counts the face-down cards from the two decks to ensure that each deck still has the correct number of cards. If the number of cards is incorrect, the deck is removed and replaced with a new one.