When many people start playing blackjack, they're not even aware that rules can vary from game to game. But rules do vary based on where you play blackjack, and it's very important to know how these rule changes can affect the house edge.

By knowing which rules affect the casino edge, you can spot the good blackjack games from the bad ones. This gives you a better shot at earning profits since you can play the most favorable tables. That said, let's look at some of the rules you should focus on since they can swing the house advantage one way or the other.

Natural Blackjack Payouts - More than anything else, natural blackjack payouts have the largest effect on the house edge. With a 6:5 blackjack payout, the casino's advantage increases by a whopping 1.4%. In order to avoid this unpleasantry, opt for tables with 3:2 blackjack payouts.

Number of Decks - Don't take a single deck blackjack game at face-value because these can sometimes include bad rules like 6:5 blackjack payoffs. But it's still worth mentioning that the house edge difference from single deck to the common six-deck games is 0.58%. A good rule of thumb to consider is that the lower the decks in play, the better your chances of winning are.

Doubling Down - Some land-based casinos only let players double down on a score of 10 or 11. Seeing as how this boosts the casino edge by 0.25%, it's much more favorable if you can double down on any score.

Dealer Action on a Soft 17 - If the dealer hits on a soft 17, the house advantage increases by 0.22%. So look for games where it's clearly written on the table that "Dealers Must Stand on a Soft 17."

Double After Splitting - It's always nice to be allowed to double down after splitting a pair. Being able to double down after splitting enables you to drop the casino edge by another 0.13%.

Resplitting Aces - One more rule that can have an impact on the house advantage involves resplitting aces. If you can resplit aces, the casino edge falls by 0.07%.