The blackjack house edge, explained
Updated 15 October 2026 · Rules referenced: six decks, dealer stands on soft 17, blackjack pays 3 to 2
Blackjack has a reputation as the casino game you can "beat". It's half true. With perfect play, the house edge is among the lowest in any casino, but it never disappears. Here's where it comes from and what changes it.
What the house edge means
The house edge is the average share of each bet the casino expects to keep over a very large number of hands. An edge of 0.5 percent means that, on average, every 100 units bet lose half a unit.
It tells you nothing about a single hand or a single evening. In the short run, results swing widely in both directions. The edge only describes the long-run average, but over thousands of hands the average is what you end up with.
Where the edge comes from
Most blackjack rules are the same for you and the dealer: same cards, same target, same bust rule. The difference is order. You act first, and if you bust, your bet is collected immediately. If the dealer then busts too, you've still lost. Both bust in a meaningful share of hands, and the house wins every one of them.
The player gets some tools in return that the dealer doesn't have:
- A 3-to-2 payout on blackjack. When you're dealt a natural you win one and a half times your bet. The dealer's natural only takes your bet.
- Doubling down lets you put more money in when you're the favourite.
- Splitting turns some bad hands into two better ones.
- Standing on low totals. The dealer must draw to 17. You can stand on 12 against a weak upcard and let the dealer bust.
Used well, these tools win back almost all of the edge the house gets from acting second, but not quite all.
How much basic strategy helps
Under this site's rules (six decks, dealer stands on soft 17, 3-to-2 blackjack, double after split allowed, no surrender) a player following basic strategy perfectly faces a house edge of roughly 0.4 percent.
A player going on instinct usually does much worse. Typical habits like never doubling soft hands, standing on 16 against a 10, splitting tens, taking insurance or copying the dealer's "draw to 17" push the edge to somewhere around 1.5 to 2 percent or more. Over time, a basic-strategy player loses roughly a quarter as much.
Basic strategy players lose more hands than they win. Roughly 42 percent of hands are won, 49 percent lost and 9 percent pushed. The edge is much smaller than that gap suggests because of the extra money won on blackjacks, doubles and splits.
Rules that change the house edge
Different tables use different rules, and small print on the felt can matter more than any decision you make. These are the approximate effects of common rule changes, compared with the rules at this table:
| Rule change | Effect on house edge |
|---|---|
| Blackjack pays 6 to 5 instead of 3 to 2 | About +1.4% (worse for the player) |
| Dealer hits soft 17 instead of standing | About +0.2% |
| No doubling after a split | About +0.14% |
| Doubling only on 10 or 11 | About +0.2% |
| Eight decks instead of six | Small increase, a few hundredths of a percent |
| Single deck instead of six | About −0.5% (better for the player), with the same other rules |
| Late surrender allowed | About −0.08% |
The 6-to-5 payout stands out. It costs more than the whole edge of a good game, and more than perfect strategy can ever win back. If a table pays 6 to 5, the best strategy decision is to find another table.
Insurance and side bets
Insurance pays 2 to 1 if the dealer, showing an ace, has a ten underneath. In a six-deck shoe that happens a little under a third of the time, but the bet needs one in three to break even. That leaves the house with an edge of around 7 percent on insurance, many times worse than the main game. It's the same bet when it's offered as "even money" on your blackjack.
Side bets such as "perfect pairs" or "21+3" usually carry edges of several percent or more. Whatever their appeal, they're not part of the low-edge game that basic strategy describes.
What the edge looks like in practice
Picture 100 hands at 10 chips each, 1,000 chips in total wagered. At a 0.4 percent edge, the average loss is about 4 chips. At 2 percent from instinctive play, it's about 20. At a 6-to-5 table it's around 18 even with perfect strategy, and over 30 with typical play.
Any single 100-hand session could easily end 100 chips up or 100 chips down. These figures are only averages, which is exactly why the house edge is easy to ignore in the moment and impossible to escape over time.
What about card counting?
Card counting tracks the ratio of high to low cards left in the shoe and raises bets when the remainder favours the player. In real casinos it can tip the edge slightly in the player's favour, but it requires large bet swings and long sessions, and casinos are entitled to refuse play to counters.
It doesn't work at this practice table, because the software reshuffles the shoe before it runs low. The fair play page explains how the shuffle works.
The honest summary: basic strategy makes blackjack about as cheap as casino entertainment gets, but it's still entertainment that costs money over time. No strategy or betting system turns it into income.
Keep learning
See which beliefs about the game don't survive the maths in blackjack myths, or go straight to the strategy chart.