Blackjack has the lowest house edge of any casino game, and almost nobody gets it. The edge is only around half a percent if you play correctly at a table with good rules — and a single bad rule, the one that pays blackjack at 6 to 5 instead of 3 to 2, roughly triples it. This guide covers the rules, the options and the table conditions that decide what the game actually costs.
The object is not to get twenty-one. It is to beat the dealer’s hand without going over twenty-one. Those are different goals, and confusing them is the root of most bad blackjack. You win plenty of hands with sixteen, because the dealer busts.
Card Values And The Basic Round
Cards two through ten are worth their face value. Jacks, queens and kings are worth ten. An ace is worth one or eleven, whichever suits the hand — and it switches automatically, so a hand of ace plus six is either seven or seventeen depending on what you draw next.
A hand containing an ace being counted as eleven is called a soft hand. Soft seventeen cannot bust on the next card, which is why soft hands are played very differently from hard ones.
The round runs the same way every time: you place a bet, receive two cards face up, and the dealer takes two — one face up, one face down. You then act on your hand. When you are finished, the dealer reveals their second card and plays out to fixed rules. Closest to twenty-one without exceeding it wins.
Read this first
Check the blackjack payout before you sit down. 3 to 2 is correct: a £10 blackjack pays £15. 6 to 5 pays £12 on the same hand, and that single change adds roughly 1.4% to the house edge — turning a 0.5% game into something close to 2%. It is the most expensive rule in the casino and it is printed on the table felt.
The Dealer Has No Choices
This is the part that makes blackjack tractable. The dealer does not decide anything. They draw to a fixed rule: hit on sixteen or less, stand on seventeen or more.
The one variation that matters is what happens on soft seventeen — an ace plus a six. Some tables have the dealer stand on it, some have the dealer hit. Standing on soft seventeen, usually marked “S17”, is better for you. Hitting it, “H17”, costs you roughly an extra 0.2%.
Because the dealer’s play is entirely mechanical, every decision you face has one mathematically correct answer that never changes. That is what basic strategy is: a lookup table of the correct action for every combination of your hand and the dealer’s up-card. Our basic strategy guide covers the chart itself.
Your Options
| Action | What it does | When it is available |
|---|---|---|
| Hit | Take another card | Any time, until you stand or bust |
| Stand | Keep your hand as it is | Any time |
| Double down | Double your bet and take exactly one more card | Usually first two cards only. Some tables restrict which totals |
| Split | Separate a pair into two hands, each with its own bet | On any pair. Re-splitting and splitting aces are often limited |
| Surrender | Forfeit half your bet and end the hand | Not offered at every table. Valuable when it is |
| Insurance | Side bet that the dealer has blackjack, paying 2 to 1 | Only when the dealer shows an ace |
Doubling and splitting are where most of blackjack’s low house edge comes from. They are the only moments the game lets you put more money in with the odds in your favour, and players who never use them are giving away a meaningful chunk of the return.
Never Take Insurance
When the dealer shows an ace, you are offered insurance: a side bet of half your stake that the dealer’s hidden card is a ten-value card, paying 2 to 1.
It sounds like protection. It is a separate bet with a house edge of around 7%, which is worse than nearly anything else in the casino. In a standard multi-deck shoe, slightly fewer than a third of the remaining cards are ten-value, and 2 to 1 requires better than a third to break even.
The same applies to “even money”, which is insurance dressed up. When you have a blackjack and the dealer shows an ace, taking even money guarantees a 1 to 1 payout instead of the 3 to 2 you would usually collect. Over time it costs you.
What each rule does to the house edge
The minor rule variations are worth a fraction of a percent each. The 6 to 5 payout and playing on instinct instead of strategy each cost roughly three times the entire house edge of a well-played game.
Rule Variations Worth Checking
Two tables labelled “Blackjack” can be materially different games. Before you play, check:
The blackjack payout. 3 to 2, always. Walk away from 6 to 5.
Soft seventeen. Dealer standing is better for you than dealer hitting.
Doubling rules. Being able to double on any two cards is better than being restricted to totals of nine, ten and eleven. Being able to double after splitting is better again.
Splitting rules. Whether you can re-split, and whether you can draw more than one card to split aces. Most tables give split aces one card each.
Surrender. A small but genuine benefit when available, and it is only correct on a handful of hands.
Deck count. Fewer decks slightly favours the player, all else equal. It matters far less than the payout.
Free tool Bankroll Calculator Work out a sensible session size and stake for a game with blackjack’s variance. Even at a 0.5% house edge, swings are larger than most players plan for, and the stake you choose matters more than the hands you play. Open the calculator →Side Bets
Most online blackjack tables offer side bets — Perfect Pairs, 21+3, Lucky Ladies and similar. They pay large multiples on specific card combinations.
They also carry house edges many times that of the main game, commonly somewhere between 2% and 10% or more depending on the bet and the paytable. Placing a £5 side bet alongside a £5 main bet roughly doubles your stake and multiplies your expected loss several times over.
That does not make them illegitimate — they are clearly labelled and priced. It does mean that a player who plays perfect basic strategy and then adds a side bet every hand has undone the entire point of choosing blackjack in the first place.
Handle with care
Blackjack’s low house edge applies per hand, and the game is fast. At a live table you might play sixty hands an hour; at an RNG table, several hundred. Expected loss is a percentage of everything you stake, so speed converts a cheap game into an expensive one without any rule changing. Our live casino versus RNG guide covers the practical difference.
Can You Count Cards Online?
No, and it is worth understanding why rather than just being told.
Card counting works because a shoe that has already dealt out its low cards is favourable to the player, and a counter raises their stake when that happens. It requires the deck to have a memory between hands.
RNG blackjack reshuffles a virtual deck before every hand. There is no continuity between hands, so there is nothing to count. Live dealer blackjack is dealt from a real shoe, but studios use continuous shuffling machines or reshuffle early enough that no usable count develops — and the multi-table, multi-player format removes the stake-variation opportunity even if one did.
Online blackjack is best treated as what it is: a well-priced, fixed-edge game where correct play gets you to roughly 0.5% and nothing gets you below it.
Worked Example: What The Payout Rule Costs
Worked example: two identical sessions
You play £10 a hand for 200 hands. Total staked: £2,000. You play basic strategy correctly at both tables.
Table A — blackjack pays 3:2, dealer stands on soft 17. House edge roughly 0.5%. Expected loss: about £10.
Table B — blackjack pays 6:5, dealer hits soft 17. House edge roughly 2.1%. Expected loss: about £42.
Same game, same stake, same strategy, same number of hands. The table you chose costs you four times as much — and the only visible difference was a line of small print on the felt.
Now add a £5 side bet every hand at a 6% edge. That is another £1,000 staked and roughly £60 more in expected loss, which is more than the entire main game costs. Figures are approximate.
Blackjack And Casino Bonuses
One practical point that catches blackjack players out: because the house edge is so low, casinos rarely let blackjack count fully towards bonus wagering.
Game weighting typically counts blackjack at 10% of the stake towards a wagering requirement, and sometimes at 0%. A £10 blackjack hand might contribute £1, or nothing, towards clearing a bonus. Some casinos go further and exclude blackjack entirely while a bonus is active, or void winnings if you play it.
The 10x wagering cap introduced in January 2026 limits the multiple but does not touch game weighting, so this remains the thing to check. Our UK casino bonus rules guide covers the full terms, and the slot rules guide covers the separate restrictions that apply to slots but not to table games.
