The blackjack insurance bet is a side bet offered only when the dealer's upcard is an ace. It costs up to half your original wager, and it wins 2:1 if the dealer's face-down card is worth ten — a ten, jack, queen or king. Everything else loses it.
That payout sounds fair until you price it. A 2:1 bet needs to win one time in three to break even. The dealer's hole card is a ten roughly 31% of the time in a normal shoe. The gap between 31% and 33.3% is the casino's margin, and it works out to about 7 cents lost per dollar insured — several times worse than the main game you are already playing. If you have not met the rest of the table yet, start with how a blackjack round actually works, then come back for the arithmetic.
What you are actually betting on when you take insurance
Insurance is not protection for your hand. It is a separate wager on one card — the dealer's hole card — settled before your hand plays out at all.
The sequence at a standard table:
- You place your main bet and receive two cards. The dealer shows an ace.
- The dealer offers insurance. You may stake up to half your original bet on a separate line; Mohegan Sun's published blackjack rules state the half-stake cap and require the decision before the hole card is checked.
- The dealer peeks. If it is a ten-value card, insurance pays 2:1 and your main hand loses (or pushes, if you also have blackjack).
- If it is anything else, the insurance stake is collected and the round continues normally.
Rules do vary. Many European and online tables deal no hole card at all, so insurance settles at the end of the round instead of immediately. Some live-dealer games auto-offer even money to blackjack hands, and most online games include a "no insurance" button that skips the prompt permanently. The payout is 2:1 almost everywhere, and that consistency is what makes the bet easy to price. Other optional wagers on the felt — Perfect Pairs, 21+3, Match the Dealer — carry their own numbers, laid out in our guide to blackjack side bet odds.
Insurance break-even math: why one in three is the line
Take a $1 insurance stake. Call the chance the hole card is a ten p. You win $2 with probability p and lose $1 the rest of the time:
EV = 2p − (1 − p) = 3p − 1
That expression is zero at p = 1/3, or 33.33%. Anything below that loses money.
Now the actual composition. Sixteen of every 52 cards are worth ten, so the baseline density is 16/52 = 30.77%. In a six-deck shoe you can see three cards — your two and the dealer's ace — leaving 96 ten-value cards among 309 unseen, or 31.07%. Plug it in: 3 × 0.3107 − 1 = −0.068. You lose 6.8 cents per dollar.
House edge on insurance by deck count and your own hand
Your own cards matter, because every ten you are holding is one fewer ten available to the dealer.
| Game and your hand | Tens unseen | Cards unseen | Dealer blackjack | Cost per $1 insured |
|---|---|---|---|---|
| Single deck, no tens in your hand | 16 | 49 | 32.65% | −2.0¢ |
| Double deck, no tens in your hand | 32 | 101 | 31.68% | −5.0¢ |
| Six decks, no tens in your hand | 96 | 309 | 31.07% | −6.8¢ |
| Six decks, you hold blackjack | 95 | 309 | 30.74% | −7.8¢ |
| Six decks, you hold 20 | 94 | 309 | 30.42% | −8.7¢ |
| Eight decks, no tens in your hand | 128 | 413 | 30.99% | −7.0¢ |
Our derivation from card composition alone: unseen cards are the full pack minus your two cards and the dealer's ace, and cost per dollar is 3 × (chance of a ten) − 1.
Read the last two rows again. Insurance is at its most expensive exactly when players most want it — holding 20 or a blackjack, with a big hand to "protect."
Is even money just insurance under another name?
Yes, and the equivalence is exact. Say you bet $100, draw a blackjack, and the dealer shows an ace.
- Take even money: you are paid $100 flat and the round is over.
- Insure the maximum $50 instead: if the dealer has blackjack, your hand pushes and insurance pays $100. If not, you lose the $50 but your blackjack pays $150. Either way, $100.
When should you never hit in blackjack?
Four situations, and none of them are close calls. Never hit a hard 17 or higher — no card improves it and five of thirteen ranks bust you. Never hit hard 12 through 16 against a dealer 2 through 6, where standing lets the dealer bust instead. Never hit a hand you should be doubling, like 11 against anything but an ace. And never hit a pair of aces or eights; split them. Full detail sits in the basic strategy chart.
When taking insurance is the right call
The bet turns positive when ten-value cards make up more than one in three of the unseen pack. That is not a hunch — it is a count. Card counters treat insurance as their single most valuable deviation, taking it once the Hi-Lo true count reaches roughly +3, and skipping it below that. In a continuously shuffled or fast-penetration online game the count never gets there, which is the practical problem with counting online.
Two smaller cases are worth knowing. In a hand-dealt single-deck game the bet costs about 2% rather than 7% — still bad, but the cheapest version of the mistake. And if you have watched a round where several tens have already hit the felt, the density has moved against you, not for you.
For the full round structure, payouts and dealer rules that surround this decision, read our complete blackjack guide.