How to Play Blackjack — Basic Strategy Guide
Blackjack is one of the only casino games where your decisions genuinely affect the outcome. With correct basic strategy, you can reduce the house edge to around 0.5% — making it the best odds you'll find at any table game. This guide covers everything from the fundamental rules to a complete basic strategy chart, so you can walk up to any blackjack table — live or online — and play with confidence.
The Rules of Blackjack
The objective of blackjack is simple: beat the dealer's hand without going over 21. Cards 2–10 are worth their face value, face cards (Jack, Queen, King) are worth 10, and Aces count as either 1 or 11 — whichever is more favourable for your hand.
Each round begins with two cards dealt to you and two to the dealer (one face-up, one face-down). Based on your cards and the dealer's visible card, you decide your action:
- Hit — Take another card.
- Stand — Keep your current hand.
- Double Down — Double your bet and receive exactly one more card.
- Split — If you have two cards of the same value, split them into two separate hands.
- Surrender — Give up half your bet and fold (not available at all tables).
The dealer must follow fixed rules: typically hitting on 16 or below and standing on 17 or above. This predictability is what makes basic strategy possible.
Understanding Basic Strategy
Basic strategy is a mathematically optimal set of decisions for every possible combination of your hand versus the dealer's up-card. It was developed through computer simulations of millions of hands and tells you the statistically best action in every situation.
The key principle: your decisions should be based on probabilities, not hunches. A hand of 16 against a dealer's 10 feels terrible — and it is — but basic strategy tells you the least costly action in that spot.
Hard Hands (No Ace, or Ace Counted as 1)
| Your Hand | Dealer Shows 2–6 | Dealer Shows 7–Ace |
|---|---|---|
| 8 or less | Hit | Hit |
| 9 | Double (if allowed), else Hit | Hit |
| 10 | Double | Double (except vs Ace: Hit) |
| 11 | Double | Double |
| 12 | Stand (except vs 2–3: Hit) | Hit |
| 13–16 | Stand | Hit |
| 17+ | Stand | Stand |
Soft Hands (Ace Counted as 11)
| Your Hand | Dealer Shows 2–6 | Dealer Shows 7–Ace |
|---|---|---|
| Soft 13–14 | Double (vs 5–6), else Hit | Hit |
| Soft 15–16 | Double (vs 4–6), else Hit | Hit |
| Soft 17 | Double (vs 3–6), else Hit | Hit |
| Soft 18 | Stand (Double vs 3–6) | Stand (Hit vs 9, 10, Ace) |
| Soft 19+ | Stand | Stand |
Pairs
| Your Pair | Action |
|---|---|
| Aces | Always Split |
| 8s | Always Split |
| 10s | Never Split — Stand on 20 |
| 5s | Never Split — Treat as 10, Double |
| 4s | Hit (Split vs 5–6 at some tables) |
| 2s, 3s, 6s, 7s | Split vs dealer 2–7, else Hit |
| 9s | Split vs 2–9 (except 7), Stand vs 7/10/Ace |
Common Mistakes to Avoid
Even players who know basic strategy make errors under pressure. Here are the most costly mistakes:
- Standing on 12 against a dealer's 2 or 3. It feels safe, but hitting is the correct play — the dealer is not as likely to bust as you think with these up-cards.
- Never doubling on soft hands. Soft 17 against a dealer's 5 or 6 is one of the most profitable double-down situations in the game.
- Splitting 10s. You already have 20. Don't get greedy — stand and take the near-certain win.
- Taking insurance. Insurance is a side bet that the dealer has blackjack. It carries a house edge of over 7% and is never worth taking unless you're counting cards.
Blackjack Variants and Rule Variations
Not all blackjack games are equal. Rule variations change the house edge, sometimes significantly:
- Dealer hits or stands on soft 17: Dealer standing on soft 17 is better for you (lowers house edge by ~0.2%).
- Number of decks: Single-deck games have the lowest house edge, but they're rare online. Most online blackjack uses 6 or 8 decks.
- Blackjack payout: Always look for games paying 3:2 for a natural blackjack. Games paying 6:5 increase the house edge by approximately 1.4%.
- Doubling restrictions: Some games only allow doubling on 9, 10, or 11. Unrestricted doubling is better for the player.
- Surrender: If available, late surrender is valuable — particularly when holding 15 or 16 against a dealer's 10.
Pro Tip: Choosing the Right Table
Before sitting down, check three things: the blackjack payout (3:2, never 6:5), whether the dealer stands on soft 17, and the minimum/maximum bet limits. These details are usually printed on the table felt in live casinos, or listed in the game rules online. A favourable ruleset can be worth more than any betting system.
Bankroll Tips for Blackjack
Blackjack has relatively low variance compared to slots, but losing streaks still happen. A practical starting bankroll is 40–50 times your minimum bet for a single session. If you're playing £10 hands, bring at least £400–£500. This gives you enough runway to weather normal swings without going broke.
Never increase your bets to chase losses. Basic strategy already gives you the best possible odds — changing your bet size doesn't change the math. Stay flat or use modest bet spreads if you're comfortable with the variance.
18+ | Play Responsibly
Gambling should be entertainment, not a way to make money. Set a budget before you play and stick to it. If you feel gambling is becoming a problem, visit BeGambleAware.org or call the National Gambling Helpline at 0808 8020 133.