Blackjack Strategy 101 – Rules, Basic Strategy & House Edge
Blackjack is one of the only casino games where your decisions actually matter. With good rules and basic strategy, you can push the house edge down to around 0.5–1%. This guide covers rules, hand values, table flow, basic strategy ideas and common traps.
1. Blackjack Rules in Plain English
The goal of blackjack is simple: get closer to 21 than the dealer without going over. You play against the dealer, not other players at the table.
Card values
- Number cards (2–10) = face value
- J, Q, K = 10
- Ace (A) = 1 or 11, whichever helps your hand most
Basic hand types
- Hard hand: a total that either has no Ace, or has an Ace that must count as 1 (e.g., 10–7 = 17, A–6–10 = “hard 17”).
- Soft hand: a total with an Ace counted as 11 (e.g., A–6 = “soft 17”).
- Blackjack: an Ace + 10-value card on the first two cards (pays 3:2 in good games).
2. Why Rules Matter for House Edge
The same basic game can have very different difficulty levels depending on the casino’s rules. Small rule tweaks move the house edge up or down.
| Rule | Effect on House Edge | Notes |
|---|---|---|
| Blackjack pays 3:2 | Best | Standard fair payout. If you see 6:5 on blackjacks, avoid the game. |
| Dealer stands on soft 17 (S17) | Lower edge | Better for players than “Dealer hits soft 17” (H17). |
| Double after split allowed | Lower edge | More flexibility to press edges in good situations. |
| Resplitting Aces allowed | Lower edge | Good rule – increases your potential in strong starting hands. |
| No doubling on some totals | Higher edge | Restrictions on doubling hurt players. |
| Blackjack pays 6:5 | Much higher edge | Big red flag; effective house edge jumps significantly. |
3. Basic Strategy: The “Correct” Way to Play Every Hand
Basic strategy is a chart of the mathematically best play for every possible player hand vs dealer up-card, assuming a specific rule set. It doesn’t guarantee wins, but it minimises your losses over the long run.
Core basic strategy ideas
- Always hit hard totals 8 or less.
- Stand on hard 17+ against any dealer up-card.
- Always split Aces and 8s; never split 5s or 10s.
- Double down on 10 or 11 against weaker dealer cards (usually 2–9).
- For soft hands (with an Ace), be more aggressive with doubles when the dealer shows a weak card.
You don’t need to memorise the entire chart instantly. Start with a simple version that covers:
- Hard totals vs dealer 2–6 and 7–A
- Soft totals (A+something)
- Pairs (when to split)
Many sites and apps offer practice trainers. Use them for 10–15 minutes at a time until most decisions feel automatic.
4. House Edge, Bankroll & Session Planning
In good blackjack games, playing basic strategy can keep the house edge around 0.5–1%. That’s excellent compared to many casino games, but it still means you pay a long-term “cost” to play.
If you wager $25 per hand and see ~60 hands an hour:
- Total amount wagered per hour ≈ $1,500
- At a 1% house edge, long-run expected loss ≈ $15/hour
Short-term, you can win or lose far more. Over many sessions, results gravitate toward that average.
Before you sit down, set:
- A total bankroll you can afford to lose.
- A per-session stop-loss (e.g., 10–20% of that bankroll).
- A rough time limit (e.g., 60–90 minutes).
5. Common Blackjack Mistakes to Avoid
- Playing 6:5 blackjack games: this single rule change can add ~1.5%+ to the house edge. Walk away.
- Ignoring soft vs hard hands: treating A-6 like a hard 7 or 17 instead of a flexible soft total.
- Overusing insurance: “insurance” is usually a negative-EV side bet unless you’re counting cards.
- Chasing losses by upping bet size randomly: often leads to burning through your bankroll during bad streaks.
- Relying on hunches over strategy: “I feel like the dealer will bust” is not a plan.
6. Online vs Live Blackjack
Online and live blackjack share the same core rules, but the experience and pace are very different.
- Online RNG blackjack: very fast hands per hour. Great for practicing basic strategy, but easy to overplay your bankroll.
- Live dealer blackjack: slower pace, more social. Rules can vary by table and provider.
- Mobile play: convenient, but you need to be extra strict with time and money limits.
Make sure any site you play on is licensed, offers fair games and has decent responsible gambling tools. For examples of what we look for in casinos, see the recommendations on the Gambling101 home page.
7. Keeping Blackjack Fun & Under Control
Blackjack is more engaging than most casino games because your decisions matter. That’s also why it can be more emotionally intense.
- Decide your entertainment budget before you play.
- Stick to basic strategy – don’t chase “hunches” after a few bad beats.
- Take breaks. Don’t try to win back losses in a single session.
- Stop immediately if you feel angry, desperate or obsessed with “getting even”.
If blackjack (or any gambling) no longer feels like optional entertainment, stop and visit Responsible Gambling for help resources in your region.
Your Next Blackjack Steps
- Read Odds Explained to connect payouts with probability.
- Review Expected Value (EV) for Gamblers to understand long-term outcomes.
- Set up a simple plan from Bankroll Management.
- Browse licensed casinos on the Gambling101 homepage if you’re ready to play for real.