A single-deck game has a lower house edge than a multi-deck game. However, casinos generally adjust other rules in their favor for single-deck games.For example, they may reduce the payout for a natural blackjack. These rule changes are made to negate the advantages of playing with a single deck of cards and ensure that the house edge does not get too low.So it doesnt really matter how many decks a game has. The house edge is more important. As mentioned earlier, the best and easiest way to reduce the house edge is to use a basic strategy.