Blackjack Basic Strategy Cards for each of the five types of Blackjack games. 1. Single Deck 2. multi-deck 3. Multi-deck Player Biased 4. Multi-deck Dealer Biased and 5. Double Deck. These cards are unique in the industry in that they cover two game types that others do not. Also, the difference in eash cards decision rules is colored red. This way the difference in each game is obvious and you can focus on learning only the rules that are different from card to card.