Online Blackjack Guide: Rules, Basic Strategy and the Bets to Avoid

Blackjack is the casino game where your decisions genuinely matter. Play every hand correctly and the house edge falls to around 0.5%, the lowest of any mainstream game. Play by feel and it climbs to 2-4%, worse than many slots. This guide gives you the rules that matter and the complete strategy to play well from your first hand.

The objective

Beat the dealer by having a hand total closer to 21 without exceeding it. Cards 2-10 count at face value, face cards count 10, and aces count 1 or 11. An ace plus a ten-value card on your first two cards is a blackjack and pays 3:2 (you win €15 on a €10 bet).

How a hand plays out

1. You place a bet. You and the dealer each receive two cards; one dealer card is face up.
2. You decide: hit (take another card), stand (keep your total), double down (double your bet and take exactly one more card), split (if your two cards match, separate them into two hands with a second equal bet) or surrender (forfeit half your bet and end the hand, where offered).
3. If you exceed 21, you bust and lose immediately.
4. The dealer then plays by fixed rules: hits until reaching 17 or more.
5. Closer to 21 wins. Ties push (your bet is returned).

Rules that change the house edge

Not all blackjack tables are equal. Before sitting down, check:

Most online tables use 6-8 decks with S17 and 3:2 payouts, giving an edge around 0.5%. Avoid any table paying 6:5 on blackjack; it is the single most expensive rule variation.

Basic strategy

Basic strategy is the mathematically correct decision for every combination of your hand and the dealer's up card. It was derived by computer simulation and does not change based on hunches or previous hands. Learn it, or keep a chart open while you play (this is allowed at every online casino).

Hard totals (no ace counted as 11)

• 8 or less: always hit
• 9: double against dealer 3-6, otherwise hit
• 10: double against 2-9, otherwise hit
• 11: double against 2-10, hit against ace (double against ace at S17 tables)
• 12: stand against 4-6, otherwise hit
• 13-16: stand against 2-6, otherwise hit
• 17 or more: always stand

Soft totals (ace counted as 11)

• Soft 13-14 (A2, A3): double against 5-6, otherwise hit
• Soft 15-16 (A4, A5): double against 4-6, otherwise hit
• Soft 17 (A6): double against 3-6, otherwise hit
• Soft 18 (A7): double against 2-6, stand against 7-8, hit against 9-ace
• Soft 19 or more: stand (double soft 19 against 6 at H17 tables)

Pairs

• Aces and 8s: always split
• 10s: never split
• 9s: split against 2-6 and 8-9, otherwise stand
• 7s: split against 2-7, otherwise hit
• 6s: split against 2-6, otherwise hit
• 5s: treat as hard 10 (double against 2-9)
• 4s: split against 5-6 only (if double after split allowed), otherwise hit
• 2s and 3s: split against 2-7, otherwise hit

Surrender (where offered)

• Hard 16 (not a pair of 8s) against dealer 9, 10 or ace
• Hard 15 against dealer 10

Bets to avoid

Insurance: offered when the dealer shows an ace. Pays 2:1 if the dealer has blackjack. The house edge is around 7%. Never take it.

Side bets (Perfect Pairs, 21+3, Lucky Ladies, Bust It): these carry house edges of 3-10% or more. They are the reason blackjack tables remain profitable despite the low main-game edge. Skip them all.

Even money: taking a guaranteed 1:1 on your blackjack when the dealer shows an ace is mathematically identical to insurance. Decline it.

Live vs RNG blackjack online

RNG blackjack reshuffles every hand, deals instantly and often accepts €1 bets. It is ideal for practising strategy.

Live dealer blackjack streams a real dealer and shoe. Standard tables seat seven players; Infinite Blackjack and similar formats accept unlimited players, each choosing their own actions. Hands take 30-60 seconds, which caps your hourly exposure. Most tables are S17 with 3:2 payouts and eight decks. Our live dealer guide covers the formats.

Whichever you choose, the odds depend only on the rules, not on the format, other players or how the dealer is "running".

Bankroll and betting

Bet flat. Progressive systems such as Martingale (doubling after losses) do not change the house edge and expose you to catastrophic losses when a streak hits the table limit. Keep bets at 2-5% of your session bankroll and stop at a pre-set loss limit. See our bankroll management guide.

Blackjack and casino bonuses

Blackjack usually contributes 5-10% towards bonus wagering, or is excluded entirely, because the casino's edge is too thin to fund a bonus. Do not use match bonuses for blackjack; look for cashback offers or play with real money. Casinos with the best blackjack selection and limits are ranked in our reviews of bet365, LeoVegas and Betsson.