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Single-deck vs multi-deck blackjack: which has the lower house edge?
Fewer decks mean a lower house edge — a single deck shaves roughly 0.15% off compared with an eight-deck shoe. So single-deck looks like the obvious winner. The catch: most single-deck tables now pay 6:5 on a blackjack instead of 3:2, and that one rule change costs you about 1.4% — far more than the deck advantage was ever worth. Here's the real breakdown.
Single-deck blackjack has a reputation as the purist's choice, and on the surface the logic holds up: the fewer decks in play, the lower the house edge. But the number of decks is only one input into the math. The blackjack payout — 3:2 versus 6:5 — is a far bigger lever, and it's the one most single-deck tables quietly pull against you. We'll separate the two effects and show you which table actually does the most to protect your bankroll.
Key differences at a glance
The headline numbers, assuming otherwise identical rules. Read on for the math behind them.
| Property | Single deck (6:5) | Multi-deck (3:2) |
|---|---|---|
| Blackjack payout | 6:5 | 3:2 |
| Decks in play | 1 | 6–8 |
| Deck-count effect | ~0.15% better | baseline |
| Payout effect | ~1.40% worse | baseline |
| Net house edge | higher (~1.5%) | lower (~0.5%) |
| Better for bankroll | — | yes |
Why fewer decks help
With fewer cards in play, a ten or an ace becomes slightly more likely to land where it helps you, and the swings tilt marginally in the player's favour. A single deck with the same rules as an eight-deck shoe lowers the house edge by roughly 0.15 percentage points. That's a real edge — it's why card counters historically loved single- and double-deck games. But on its own it's small, and casinos know exactly how to claw it back.
The 6:5 payout trap
A natural blackjack — an ace plus any ten-value card as your first two cards — is the best hand in the game. The fair, traditional payout is 3:2: bet CA$10, win CA$15. Many single-deck tables now pay only 6:5: bet CA$10, win just CA$12. You hit a blackjack roughly once every 21 hands, and over a session that missing CA$3 per natural adds up fast. Switching a table from 3:2 to 6:5 adds about 1.4 percentage points to the house edge — nearly ten times the deck advantage you were chasing.
Blackjack payout: 3:2 vs 6:5
What a winning natural pays at common bet sizes.
| Your bet | Pays at 3:2 | Pays at 6:5 | You lose |
|---|---|---|---|
| CA$10 | CA$15 | CA$12 | CA$3 |
| CA$25 | CA$37.50 | CA$30 | CA$7.50 |
| CA$50 | CA$75 | CA$60 | CA$15 |
| CA$100 | CA$150 | CA$120 | CA$30 |
| CA$200 | CA$300 | CA$240 | CA$60 |
House edge: putting it together
Start with a typical multi-deck game on good rules — six or eight decks, dealer stands on soft 17, double after split allowed, blackjack pays 3:2. That sits at around a 0.5% house edge.
Single deck, 3:2 payout: this is the genuinely best version — cut the deck count, keep the fair payout, and the edge can drop below 0.2%. The problem is that these tables are now rare, especially online.
Single deck, 6:5 payout: take that same single-deck game, switch the natural to 6:5, and the edge jumps to roughly 1.5% — three times worse than the 3:2 multi-deck table. The deck advantage is real but tiny; the payout penalty dwarfs it.
In other words: a 6:5 single-deck table is one of the worst common blackjack bets on the floor, despite the 'single deck' label that's meant to sound premium.
What to check before you sit down
Always read the table felt and the game info panel before you bet. The payout line is the single most important number: if it says 'Blackjack pays 6 to 5', walk away — even a six- or eight-deck 3:2 table beats it comfortably. After the payout, the rules that matter most are whether the dealer stands or hits on soft 17, whether you can double after splitting, and how many splits are allowed. Our /ca/rules/ guide breaks down each one, and the /ca/strategies/ hub shows how correct basic strategy moves the edge further.
Why 6:5 single-deck tables exist
Casinos love marketing a single-deck game because experienced players associate a single deck with a low house edge. The 6:5 payout is the quiet trade-off that makes it profitable for the house — most casual players never notice the payout line, only the 'single deck' sign. It's the same psychology that sells worse odds under a better-sounding label. Knowing to check the payout is the single biggest skill edge a recreational player can have.