Blackjack is one of the few casino games where your decisions genuinely matter. Basic strategy gives the mathematically best play for every situation: hit, stand, double or split. It is just as important to understand what it does not do. No strategy changes the house edge in your favour. A game's published RTP already assumes perfect basic strategy, and every deviation from it only adds to the casino's edge.
This guide covers the key basic strategy rules, why card counting does not work online, and why side bets cost more than the main game.
Basic strategy is a chart worked out for every starting hand against every dealer up card, using only your cards and the dealer's visible card. Rule differences such as the number of decks or whether the dealer stands on soft 17 change a few borderline plays, but the core stays the same. Played perfectly, multi-deck blackjack with standard rules has a house edge of around half a per cent. That edge is small but it does not disappear; strategy simply stops you paying extra for mistakes, which can easily multiply the edge for players going on instinct.
A blackjack strategy chart lists your own cards down the left side and the dealer's up-card across the top. You find your hand on its row and the dealer's card in its column, and the cell tells you the right move: hit, stand, double or split. Charts usually come in three parts: hard hands, soft hands and pairs.
Using the chart is easier once you remember two ideas. Against weak dealer cards, 2 to 6, the dealer busts more often, so you should avoid unnecessary risks. Against strong dealer cards, 7 to ace, your hand usually needs to improve until it reaches at least 17. The key hard-total and pair rules are summarised below.
The chart is calculated for a particular set of rules, so the table rules can change a few cells. No chart removes the house edge: it only keeps the extra cost of mistakes as small as possible.
These rules assume a multi-deck game where the dealer stands on soft 17 and doubling after a split is allowed. Dealer cards 2–6 are weak because the dealer often has to draw several cards and busts more often; 7 to ace are strong.
Counting relies on dealt cards changing the make-up of the remaining deck. When many tens and aces are left, the odds briefly tilt towards the player and a counter raises the bet. RNG blackjack typically reshuffles after every hand, so each round starts from a full deck and past cards tell you nothing. Live tables deal from a real shoe, but they usually use six to eight decks and reshuffle well before the shoe runs out, so any advantage is small, rare and would need large bet swings to use. In practice, counting is not a workable approach online.
Many blackjack games offer side bets that pay on, for example, a pair in your first two cards or a poker hand formed with the dealer's up card. The payouts can be large, but so is the edge: side bets typically carry a house edge of several per cent, against about half a per cent for the main game with basic strategy, and there is no strategy to reduce it. To make your bankroll last, focus on the main game.
Basic strategy, which gives the mathematically best decision for every hand. It keeps the house edge as low as possible but does not remove it.
Not in your favour. A game's published RTP already assumes perfect basic strategy; the strategy only stops you losing more than the maths requires.
Not in practice. RNG games typically reshuffle after every hand, and live tables use several decks and reshuffle early.
Side bets usually carry a house edge many times higher than the main game. They add variety, but on average they cost you more.
A strategy chart is a grid showing the correct move for your hand against the dealer's up-card. The rules in this guide match the chart for a typical multi-deck game. Always check the table's own rules, as they can change some cells.
Find your cards on the left and the dealer's up-card along the top. The letter or word in the cell gives the move: hit, stand, double or split. Start with hard hands and pairs, as they come up most often.