Blackjack – Definitive Guide (2024)

  • 7 mins read

A simple explanation of all the rules of blackjack. Also, an easy way to do card counting. But, find out why card counting is usually useless online.

  • After covering the rules of blackjack, we explain how to count cards in Blackjack using the simple Hi-Lo system, and explore the circumstances it may work in a live casino.
  • However, we also explain why card counting is unlikely to work online (with one interesting exception).
  • Find it all in our complete Blackjack guide.

What are the rules of Blackjack?

Blackjack is played between a single dealer (i.e. the casino), and one or more players.

blackjack rules

Each player who has placed an initial bet gets dealt two cards face down. The dealer gets dealt 1 card face up (and another face down, or alternatively this 2nd card may be dealt later after all the players have played their hands).

What is the ultimate aim of blackjack?

  • The player wins if their hand is worth, more points than the dealer at the end of the game.
  • However, getting more than 21 points is a bust for either the player of dealer.
  • The player can decide what strategy (if any) to use as regards to taking further cards after the first two compulsory cards dealt to them.
  • The dealer has to follow the rules of the specific variation of the game.
  • The player wins if the dealer busts before them, however they lose if they bust before the dealer.


In blackjack, the cards represent points. Suits don’t matter.

  • T/J/Q/K are worth 10 points.
  • An Ace can be worth 11 or 1.
  • All other cards are worth the same number of points as their number, i.e 6 is worth 6 points.

Decisions & outcome

Unlike a game like bingo, each player makes important decisions during the game.

  • As long as you don’t have more than 21 points, you can keep taking cards (‘hit’). By taking cards you can get closer to 21, but you could also bust, which is why you might want to not take any further card and end your turn instead (‘stand’).
  • You could decide to double your initial bet, and commit to taking exactly 1 further card.
  • You could split (if your first two cards dealt have the same value or rank depending on the casino’s rules). This means you can play 2 hands by splitting your hand into 2 and getting an addition card for each – a 2nd bet is required).
  • You could surrender (where available, the casino returns half your initial bet, but removes you from this hand).

After all the players have played, the dealer must hit until they have 17 or more points, at which time they must stand. If the dealer is showing a soft 17 (this is 17 points, involving an ace for 11 points), in some casinos the dealer must hit. If the dealer busts, all players who did not bust win. But, if the dealer does not bust, all player with points greater than the dealer win. Ties means no one wins, players initial bets are returned.

What is Blackjack card counting?

blackjack card counting

Blackjack Card Counting is a method used by players aiming to give themselves an advantage over the casino. In blackjack playing a perfect strategy (i.e. making the best decisions every time) without any card counting, still gives the casino an edge of around 0.5%.

However, card counting can give the player an edge over the casino upto 2%.

Why does blackjack card counting give the player an edge?

  • By keeping track of the high and low cards already dealt to the player / other players / dealer during this and previous hands, it is possible to understand whether the remaining cards are high / low / neutral.
  • In blackjack high cards are good for the player, whilst low cards are not. The card counter will bet (or place bigger bets) when they calculate they have the advantage (i.e. the more high cards left the better).
  • Conversely, they will avoid betting (or place smaller bets) when they calculate the casino has the advantage (when the remaining cards are mostly low). Understanding information about the remaining cards, also allows the card counter to make better decisions during each hand.

Why are higher cards favourable to blackjack players?

  • The reason higher cards are favourable to the player is players are paid out at 1-1 (evens) if they win. However, if they make a blackjack (also called a natural) these can pay out at 3-2 (this will be less at some casinos). Obviously the possibility of hitting a blackjack, is higher if there are more high cards left in the deck.
  • Doubling down (doubling you wager, before taking exactly one more card) is more likely to be successful in certain situations.
  • Insurance bets (which otherwise should be avoided) might be a profitable bet. Insurance bets pay out at 2-1, and can be made whenever the dealer shows an ace as their first card. As the payout is 2-1, if from your card count you know the dealer’s 2nd card has a better than 1 in 3 chance of being worth 10 points, this bet will be a profitable bet in the long run.
  • Also high cards might mean the dealer is more likely to bust than the player, as the dealer has to take a card based on predetermined rules, which the player can choose not to take a card even when they would have had it not been for their knowledge of the card count).
  • Furthermore, more splits may be possible.

Hi-Lo card counting system

There are many different systems for card counting, and there is no need to keep track of the actual cards dealt. A basic system called the hi-lo system.

How to use the H-Lo card counting system. Start the count at 0.

  1. Deduct 1 from the count

    …for every 10/J/Q/K/A dealt

  2. Add 1 to the count

    …for every 6/5/4/3/2 dealt

  3. Do nothing

    …for any other cards dealt

  • In the hi-lo system the running count never increases/decreases by more than the same number (level 1 count).
    • This type of count is the easiest to do without much effort required, or the possibility of making mistakes.
  • There are more advanced systems, such as higher level counts, which involve adding/subtracting different numbers based on the cards dealt.
    • Even if these counts could produce more accurate results, you need to take account of the possibility of making errors might also increase if your method becomes more complicated.

Countermeasures casinos use against card counting

  • The fewer cards that remain in the deck, the better idea, the card counter will have about the remaining cards. This means single-deck games are ideal for card counters, who can make increasingly accurate decisions as more cards are used. Casinos can use multiple decks shuffled together, and reshuffling whilst perhaps the equivalent of one deck remains un-dealt, to avoid the card counter having this advantage.
  • The legality of card counting is dependent on local laws. However generally, unless technology is being used it is not illegal. Casinos may ban players from blackjack (or even altogether) if they believe they are card counters. This ban might involve blacklisting from other casinos too.

Online casinos can easily prevent card counting altogether, by shuffling after every hand, making card counting useless. Having said that you may find some games online where this doesn’t happen, such as a live video streaming casino (a human dealer deals real cards, shown as a streaming live video, but players bet online).