When it comes to table games, blackjack is undoubtedly the most popular casino game in the world. Almost everyone understands the basic rules, and hundreds of books have been written about it. The combination of fast action, strategy, and one of the lowest house edges in the casino has made it a timeless classic – and an obvious game for online casinos to offer to their clients.
Online blackjack is hugely popular, with most online casinos offering multiple forms of the game (many of which we’ll talk about on other pages). In most respects, the rules found in a real world casino will be the exact same as those found in blackjack online. Usually, the only differences will be that the action moves a little faster, and that the cards are reshuffled after each hand. At some online casinos, you may even have the option of playing with a live dealer via streaming video!
- Our choice of the best blackjack sites
- How to play?
- Player options during a hand
- How real money games work online
- Is it possible to beat the house?
- Basic strategy
- Card counting
- Odds and typical house edge
Online blackjack games can have rules that vary slightly, but for the most part, the general framework of the game will be similar to the one we describe here. A hand begins with the player making a bet. The dealer then deals two cards each to the player and the dealer. The player’s cards are both dealt face-up, while the dealer will have one card face up (the “up card”) and one face down (the “hole card”). The object of the game is to make a hand worth as close to 21 points as possible, without going over.
Each card is assigned a number of points based on its rank. Numbered cards are worth a number of points equal to their rank (i.e., a four is worth 4 points). Tens and face cards are worth 10 points. Finally, aces are worth 11 points, unless they would cause a hand to go over a total of 21; in that case, they are worth 1 point. If at any point the player or dealer hand goes over 21 points, that hand is said to have “busted.”
A hand with an ace that is still worth 11 points is known as a “soft hand,” because it cannot go bust; if the hand would go over 21 points, the ace would revert to being worth 1 point instead. Other hands are known as “hard hands.”
The best possible starting hand is an ace plus a card worth 10 points. This totals 21 points, and is known as a blackjack. If the dealer’s up card is a ten or an ace, the dealer will check for blackjack. If the dealer has 21, it is immediately revealed, and all player hands lose – except for players who also have been dealt 21, which results in a push. It’s worth noting that before the dealer checks, the dealer will offer the player insurance. The insurance bet costs half the amount of the original bet, and pays 2-1 if the dealer has a blackjack.
Essentially, the combination of losing the original bet but winning the insurance bet causes the player to break even for the hand, “saving” their original wager. If the dealer does not have 21, the insurance bet loses, and the hand continues as normal. If the player has 21 the dealer will typically offer the player “even money” on their hand; this is, mathematically speaking, the exact same bet as the insurance bet. If the dealer does not have a blackjack, the hand continues. Players with twenty one win immediately at 3-2 odds. If a player does not have a blackjack, the player has several options for playing their hand.
At any time, a player may choose to stand. This means the player will take no further cards for their hand.
If the player chooses to hit, the dealer will give them one additional card for their hand. A player may choose to hit as many times as they like, until they either go over 21 and bust, or decide to stand.
Doubling down is available to the player only on their initial two card hand. If the player chooses to double down, they must make a second bet equal in size to their original wager. The player will then receive one more card from the dealer, after which they must stand. The player now stands to win or lose both bets depending on the outcome of the hand.
If the player was dealt two cards of the same rank, they have the option to split them into two separate hands. Each of these new hands will be dealt a second card, and each hand will be played for a full bet. Typically, players will be allowed to do anything they wish with these new hands, including doubling down or splitting again (resplitting is usually only allowed for up to a maximum of four hands). However, in most games, players do not get these options when splitting aces – they will simply receive one card for each ace and be forced to stand at that point. In addition, “blackjacks” after splitting will normally only count as 21 points, and not as an automatic win at the higher 3/2 odds.
In some games, players will be given the option of surrendering their hand. A player who surrenders gives up on the hand, forfeiting half of their bet. The other half is returned to them. There are two variations of this rule. In late surrender, the player may choose to surrender after the dealer checks for blackjack. In early surrender, the player may choose to surrender before the dealer checks. If at any point a player busts, they immediately lose the hand, and the dealer collects their bet. After all players have busted or decided to stand, the dealer reveals their down card.
Dealers are required to play their hands according to very strict rules that are usually printed on the table. In most games, dealers are required to hit with hands of 16 or less, and must stand with hands of 17 or more, regardless of what hands the players hold. In some games, however, the dealer will also be required to hit on a soft 17. If the dealer goes bust, all players who are still in the hand win even money on all bets. If the dealer stands, the dealer’s hand is then compared to each player hand. If the dealer hand is higher, the player loses their bet. If the player hand is higher, the player wins even money on their bet. If the two hands are equal, the bet is considered a push.
This image from an online blackjack game shows the options available to the player during a hand
As we mentioned earlier, there’s no shortage of online casinos for you to choose from. It’s unlikely that there’s a single casino site out there that doesn’t have at least one blackjack game, and most have several different versions of it to choose from. Oftentimes, these different games will have various side bets, and are otherwise identical. In other cases, the number of decks or some other rules may be different; this means that one game might be better for the player than another one at the same casino.
There are other factors to consider when you play blackjack for real money. At some casinos, you’ll have the opportunity to play in tournaments, while others offer special perks like games dealt by live dealers. However, for most players, choosing the best place to play will come down to where the house edge is lowest, and where the games are the most fun to play. Below, we’ve picked out some of our favorite places to play 21 online.
There is no one strategy that’s appropriate for every online blackjack game. There are hundreds of different online casinos that offer dozens of different variants of blackjack; since each game may have slightly different rules, the correct strategy for each one is also different.
The first element of blackjack strategy is what’s known as basic strategy. Basic strategy is the collection of mathematically best plays for every situation you might encounter during a hand. Each game has a slightly different basic strategy depending on the exact rules being used, including the number of decks, whether the dealer hits or stands on a soft 17, surrender rules, and other factors.
While publishing a comprehensive list of strategies for every one of these would be nearly impossible, there are shortcuts possible for players who want to learn a simple strategy that comes close to emulating the basic strategy for most the commonly played variants. The following simple strategy doesn’t require you to memorize the right play for every situation, or search a large chart while you’re playing. For most games, the house edge when using this strategy should be no more than 0.2% higher than with perfect basic strategy.
It’s also worth mentioning that this strategy is similar to one developed by Michael Shackleford, and his work was invaluable in the development of our strategy.
Our simple strategy is divided into three parts: what to do with hard hands, what to do with soft hands, and what to do with pairs.
- With hard hands of 8 or less, always hit.
- With a hard hand of 9, double if the dealer’s up card is in the range of 3-6; otherwise, hit.
- With a hard hand of 10 or 11, double if the dealer’s up card is lower than your hand’s total; otherwise, hit.
- With a hand hard of 12-16, hit if the dealer is showing a 7 or higher; otherwise, stand.
- With a hard hand of 17 or higher, always stand.
- If you are supposed to double down but cannot, hit instead.
- With a soft hand of 15 or less, always hit.
- With a soft hand of 16-18, double down if the dealer’s up card is in the range of 3-6; otherwise, hit.
- With a soft hand of 19 or higher, stand.
- If you are supposed to double down but cannot, hit instead (except with a soft 18; in that case, stand).
- With a pair of eights or aces, always split.
- With a pair of fours, fives or tens, never split.
- With a pair of twos, threes, sixes, sevens or nines, split only if the dealer is showing a 6 or less.
- If you do not split, play the hand as normal based on the above guidelines for hard and soft hands.
- Surrender (if allowed) with 16 against a ten or an ace.
- Never take insurance!
To clarify that last rule, it’s important for all serious players to know that under any basic strategy, players should never take insurance or even money on blackjacks. The house edge on insurance is over 7% (varying slightly depending on the number of decks being used), which is much higher than the standard game, even for players using relatively poor strategies.
A chart displaying perfect basic strategy. Our simpler version above has almost the same house edge
For internet blackjack, card counting simply isn’t an option. In most cases, the casinos “reshuffle” the entire shoe after each hand, meaning there is never any true deck penetration. This is even more effective than the automatic shuffling machines employed in many live casinos, and means that regardless of what cards have come out on even the previous hand, all cards are equally likely to be selected for your next hand.
While card counting is not effective for online play, we will still outline a very basic card counting system for those who are interested in understanding the basics of how they work! Card counting relies on the fact that some cards are better for the player than others; a shoe that is still rich in those cards – namely, tens, aces and (to a lesser extent) other high cards – can actually tilt the odds in the player’s favor against the house. Conversely, fives and other low cards are bad for the player, and make the odds better for the house. By tracking which cards have removed from the deck, the player is able to wager more money on hands in which the odds are in their favor, and less money (or none at all) when things are looking bad for them.
In addition, players may be able to make informed decisions on surrendering, taking insurance, or violating basic strategy based on the cards that have been removed from the shoe. The simplest card counting systems are known as “Ace-Five” systems. These card counting techniques only require the player to track the number of aces and fives being removed from the deck during play. Each ace that is removed from the deck is counted as a -1; each five that is seen adds +1 to the count. Here is an example that shows how such a system might work.
The player starts with a count of 0, and makes a small wager – perhaps the minimum allowed at their table. This bet size is known as a “unit.” If the count reaches +2, the player should double their bet to two units until the count drops back down. If the count reaches +4, the player should raise their bet to three units. After that point, add an additional unit for every +1 added to the count.
At the beginning of each shoe, fall back to betting your initial one unit bet. Obviously, much more precise and intricate systems are available for players to use, many of which can produce rather sizable advantages for the player – presuming they can avoid detection by the casino, which may choose not to allow known card counters to play in their games. However, even the simple Ace-Five systems like the one outlined above are powerful enough to reduce or eliminate the house edge from most blackjack games.
As we mentioned earlier, the rules of blackjack vary greatly from game to game. Online casinos therefore, can have very different odds depending on the rules that are being employed. For a baseline, let’s talk about a game with the following rules:
- An eight deck shoe
- Dealer stands on soft 17
- Players are allowed to double on any two cards, or after a split
- Players can resplit up to four hands, but cannot resplit aces, or hit split aces
- Late surrender is not allowed
- Blackjacks pay 3-2
This game has a house edge of approximately 0.45%, and is a typical form of the game that can be found either online or in a brick-and-mortar casino. However, several common rule changes can alter the house advantage, sometimes significantly.
For instance, reducing the number of decks used in the shoe is a surefire way to improve the players’ odds. A single deck game will reduce the house edge by .48%, while a double deck game lowers the house edge by .19%. Other rule changes that can help the player include the ability to surrender (.08%), allowing the player to draw more cards after splitting aces (.19%), or allowing players to surrender before the dealer peaks for blackjack (.24% if this is allowed against a ten, and another .39% if it is allowed against an ace).
Of course, casinos aren’t usually in the business of giving players something for nothing, and there are also many rules that can tilt the balance back in the casino’s favor. The most insidious of these is paying only 6-5 on a blackjack. Most online variations of 21 do not resort to this tactic, but it is becoming increasingly common in live casinos, particularly in single deck games. This rule has a devastating effect, adding 1.39% to the house edge.
Luckily, you won’t run into short paying blackjacks too often, but there are other rules that can hurt your chances, too. If the dealer is required to hit on a soft 17, that adds about 0.22% to the house edge. Other rules that can hurt the player include not allowing the player to double down after splitting hands (.14%), or limiting how many hands the player can split (0.10% if the player can only split to two hands, or 0.01% if the player can split to three hands).