Blackjack Terms: The Complete Glossary
Every term you'll hear at a blackjack table or read in a strategy guide, defined in plain English - from the basics (what's a push?) to the advantage-play vocabulary (what's penetration?). Each entry links to the full strategy behind it.
The Basics
- Natural (Blackjack)
- An Ace plus a ten-value card as your first two cards, totaling 21. Pays 3:2 at a fair table ($15 on a $10 bet) and beats everything except a dealer natural, which pushes. A 21 made with three or more cards is not a natural and pays even money. Full game rules →
- Ace (1 or 11?)
- An Ace counts as 11 whenever that doesn't bust the hand, and 1 otherwise - the count adjusts automatically, always in your favor. A,7 is 18; A,7,10 is also 18 because the Ace drops to 1. You never choose the value; the hand simply takes the best legal total.
- Push
- A tie. Your total equals the dealer's, nobody wins, and your bet is returned. Pushes happen in roughly 8-9% of hands. A player and dealer both busting is not a push - you lose, because you busted first. That ordering is the entire source of the house edge. Why the house has an edge →
- Upcard
- The dealer's face-up card, and one half of every basic strategy decision. A 2-6 upcard is a 'bust card' (dealer breaks 35-42% of the time); 7-Ace is a strong card. The entire strategy chart is a grid of your hand against the dealer's upcard. The strategy chart →
- Hole Card
- The dealer's face-down card. In American blackjack the dealer takes it immediately and 'peeks' when showing an Ace or 10 to check for a natural. European games deal no hole card until players finish, which changes correct strategy on doubles and splits against strong upcards.
- Stiff Hand
- A hard total of 12 through 16 - too weak to feel safe standing, one card from busting when you hit. About 4 in 10 hands pass through the stiff zone, which is why playing them correctly matters more than any other skill in basic strategy. Playing the danger zone →
- Five-Card Charlie
- A house rule where drawing five cards without busting wins automatically. Almost no real casino offers it - it's worth about 1.46% to the player, far too generous. If you see it advertised, read the rest of the rules carefully; something else is paying for it.
Player Decisions
- Hit / Stand
- Hit: take another card. Stand: keep your total and end your turn. Signaled at a live table by tapping the felt (hit) or waving a flat hand (stand) - spoken words don't count on camera.
- Double Down
- Double your bet after seeing your first two cards, in exchange for receiving exactly one more card. The chart doubles when the dealer is weak and your draw is strong - 11 vs 2-10 (and vs an Ace when the dealer hits soft 17), 10 vs 2-9, 9 vs 3-6, and a band of soft hands against 3-6. Doubling strategy →
- Split
- Turn a pair into two separate hands, each with a bet equal to your original. Always split Aces and 8s, never 10s and 5s; everything else depends on the upcard and the DAS rule. When to split, fully mapped →
- Surrender
- Give up your hand immediately and keep half your bet. 'Late' surrender (after the dealer checks for blackjack) is the common form. Correct only for the very worst matchups: 16 vs 9, 10, or Ace, and 15 vs 10. Casinos rarely advertise it - ask. Surrender strategy →
- Insurance
- A side bet offered when the dealer shows an Ace, paying 2:1 if the dealer has a natural. The true odds are worse than 2:1 unless you're counting cards, making insurance one of the worst standard bets in the casino for a basic strategy player. Decline it. The insurance mistake →
- Even Money
- Taking a guaranteed 1:1 payout on your own natural when the dealer shows an Ace, instead of risking a push. It's mathematically identical to taking insurance - and just as wrong. Decline it and accept the occasional push.
Table Rules
- S17 / H17
- Whether the dealer Stands or Hits on soft 17 (A,6). H17 adds about 0.22% to the house edge and changes several plays - more doubles against weak cards, more surrenders against an Ace. Printed right on the felt; always check before sitting. Soft 17 strategy →
- DAS (Double After Split)
- Permission to double down on hands created by splitting. Worth about 0.14% to the player, and the reason marginal splits like 2,2 vs 2 or 4,4 vs 5 exist at all. Without DAS, those hands are hits. The DAS-dependent splits →
- 6:5 Blackjack
- A payout rule where a natural pays $12 on a $10 bet instead of $15. That single change adds about 1.4% to the house edge - roughly quadrupling the cost of an otherwise good game. The most expensive two characters on any table placard; walk past these tables. What every rule costs →
- Shoe
- The box holding the shuffled decks, usually 6 or 8 of them. 'Shoe games' are the multi-deck standard; hand-held single and double deck games still exist at higher minimums, usually with worse rules attached. How many decks casinos use →
- Penetration
- How deep into the shoe the dealer goes before reshuffling - 'good pen' means 75-85% of cards dealt. Meaningless for basic strategy, everything for counters: the count only becomes reliable deep in the shoe, which is why counters hunt penetration the way tourists hunt cheap buffets. Why penetration matters →
- Cut Card
- The colored plastic card a player inserts after the shuffle to cut the decks; the dealer places it again at the reshuffle point, where it sets the penetration. When it appears mid-shoe, the current round finishes and the shuffle follows.
Advantage Play
- Basic Strategy
- The computed best response to every combination of your hand and the dealer's upcard, assuming no knowledge of the remaining cards. Cuts the house edge to about 0.5%. Not opinion, not a system - arithmetic. The complete guide →
- Card Counting
- Tracking the ratio of high to low cards left in the shoe to know when the player has the edge, then betting more. Legal everywhere in the US when done with your brain alone - though casinos can still show you the door. Card Counting 101 →
- Running Count / True Count
- The running count is the raw Hi-Lo tally of cards seen; the true count divides it by decks remaining to make it comparable at any shoe depth. Betting and playing decisions key off the true count, not the running count. The difference, explained →
- Deviation (Index Play)
- A departure from basic strategy triggered by the count - standing on 16 vs 10 at true count 0 or higher is the most famous. The Illustrious 18 covers the deviations worth the memory space. The Illustrious 18 →
- Risk of Ruin
- The probability of losing an entire bankroll before the edge pays off. The number that separates properly-bankrolled counters from gamblers with a system. Professionals size bets to keep it under 2%. Calculate yours →
- Backoff / Barring
- The casino's response to suspected counters: a 'backoff' politely restricts you to flat betting or asks you to leave the blackjack pit; barring bans you from the property. Neither involves the police - counting isn't a crime. What actually happens →
Frequently Asked Questions
Is an Ace 1 or 11 in blackjack?
Both - it counts as 11 whenever that doesn't bust your hand and 1 when it would. The value adjusts automatically in your favor: A,7 is 18, but draw a 10 and the hand is 18 again (1+7+10), not 28. You never have to declare a value.
What is a push in blackjack?
A tie between your total and the dealer's. Your bet is returned and nobody wins. The critical asymmetry: if you bust, you lose immediately even if the dealer later busts too - that ordering, not the payouts, is where the house edge comes from.
What is a 5-card charlie?
A rule where drawing five cards without busting is an automatic win. It's worth about 1.46% to the player, which is exactly why real casinos almost never offer it. Treat any table advertising it as a prompt to read the other rules very carefully.
What does blackjack pay?
A natural should pay 3:2 - $15 on a $10 bet. Tables paying 6:5 ($12 on $10) add roughly 1.4% to the house edge, making them among the worst standard blackjack games in the casino. The payout is printed on the felt; check it before you sit.