How Many Decks Are Used in Blackjack? Know Before You Play

Looking at the Number of Decks Is Key If You Want to Be a Successful Blackjack Player

Look at the Decks!

One detail many gamblers overlook is the number of decks casinos use in card games. At first glance, it feels trivial; after all, a deck is a deck, right? Why would it matter if one or several are used? The reality is that it matters a lot. The fact is that it does matter a great deal. 

The more decks there are, the odds are influenced by what strategies you can use, and at the end of the day, your potential of leaving as a winner. If you have ever wondered how many decks are used in blackjack, how it affects your strategy, well, we’ve got the answers.

How Many Decks Are Used in Blackjack?

There isn’t a single universal rule. Depending on where you play, casinos may use anywhere from one to eight decks. Each deck has the standard 52 cards for blackjack, and the card values in blackjack remain consistent: face cards are worth 10, number cards carry their own value, and the ace can swing between 1 and 11.

Some blackjack variations even tweak this formula. In Spanish 21, for instance, all tens are removed, leaving 48 cards per deck. These small changes might seem cosmetic, but they have a noticeable impact on the odds.

It’s almost impossible to find a real single-deck game in Las Vegas and most other casinos these days. Partly because it is far easier to count cards with only one deck. 

By adding decks, the casinos lower the efficacy of that strategy and also make the game safer and more sustainable for both sides. Various decks also help prevent action from stalling. The more cards you have, the fewer times you have to reshuffle, and the more comfortable your game will be.

How Many Decks for Blackjack Do Casinos Use?

If you walk into a casino and play blackjack for real money, chances are you’ll face six or eight decks. That means between 312 and 416 cards are in circulation at once.

This matters because the number of decks influences the probability of hitting blackjack and other key outcomes. Let’s take a simple example:

In a single-deck game, if your first card is an ace, you’ve got a 31.4% chance of drawing a 10-value card for blackjack.

In an eight-deck game, those odds dip to 30.8%. Out of 415 remaining cards, 128 are worth 10 points.

That 0.6% difference looks small, but over hundreds of hands, it stacks up. The same logic applies to doubling down, splitting pairs, and other moves—more decks generally mean a higher house edge and slightly tougher conditions for players.

Is Single-Deck Blackjack Always Better?

Some players chase the single-deck tables, thinking fewer decks equals better odds—and technically, they’re right. But casinos know this, which is why single-deck games usually come with strings attached.

You’ll often find stricter rules, such as reduced payouts (6:5 instead of the traditional 3:2), limits on doubling down, or higher table minimums. Sure, card counting is easier, but that advantage is watered down by the restrictions. And don’t forget: casinos don’t welcome counters. If staff suspect you’re tracking the count, they’ll politely—or not so politely—ask you to leave.

Why isn’t counting cards allowed?

Card counting isn’t illegal. It’s simply using your brain to track a pattern in the game. But from a casino’s perspective, it cuts into profit margins. Since casinos are private businesses, they reserve the right to remove anyone they believe is gaining an unfair edge.

And while Hollywood has glamorized card counting, the reality is far less cinematic. It demands constant focus, lightning-fast calculations, and the ability to mask what you’re doing while still enjoying the game. Very few people can pull it off effectively, especially in a noisy, high-pressure casino environment.

What if a casino blackjack dealer handed you a Joker?

As we mentioned, depending on the version you’re playing, all cards may or may not be used. However, regardless of the version, you’ll never find the Joker among the cards to be used. 

If, for some reason, the dealer were to hand out a joker, he would immediately stop the game and all payouts and plays, and would proceed to alert the pit boss that the game has been compromised. 

All payments and plays would be voided, and all cards would be removed from the game. A deck without a joker would be handed to the dealer to resume play while the pit boss investigates what happened.