What Stake publishes about Originals Blackjack
Stake's lobby has two kinds of blackjack: the Blackjack in the Stake Originals group, dealt by software from your seeds, and live-dealer tables from outside studios. This page is mostly about the Original, because it is the one with published rules, a stated return and cards you can recompute. Its game page shows an RTP badge of 99.43%, and Stake's house-edge guide lists "Stake Originals Blackjack: 99.43% (0.57% house edge)" with the note "Rules and decisions affect the edge" (both 1 Nov 2026).
| Rule | What Stake states | Where |
|---|---|---|
| Decks | "Unlimited decks in play" | Game rules panel (1 Nov 2026) |
| Dealer | "Dealer stands on soft 17." | Game rules panel (1 Nov 2026) |
| Blackjack payout | "A natural Blackjack … has a 3:2 payout"; other wins pay 1:1 | Game page (1 Nov 2026) |
| Insurance | Offered only when the dealer shows an Ace; pays 2:1 if the dealer has blackjack | Game page and rules panel (1 Nov 2026) |
| Both have blackjack | "then the result is a push" | Game rules panel (1 Nov 2026) |
| Doubling | "You can double on a split." | Game rules panel (1 Nov 2026) |
| Splitting | "You can only split once." "You cannot hit on split aces." | Game rules panel (1 Nov 2026) |
| RTP | 99.43%, a 0.57% house edge | Game-page RTP badge and house-edge guide (1 Nov 2026) |
| Minimum bet | $0.0001 or the equivalent | Help centre, "Crypto: Casino Betting Limits" (12 Nov 2026) |
| Maximum bet and profit | Per coin for all Stake Originals, e.g. 100 BTC bet and 20 BTC profit | Same help-centre article (12 Nov 2026) |
Two of those lines do most of the work. Blackjack paying 3:2 and the dealer standing on soft 17 are the player-friendly versions of the two rules that vary most between tables. The restrictions run the other way: one split only, and split aces receive one card each.
Unlimited decks: what it changes
Stake's fairness documentation explains the dealing model: "we utilise an unlimited amount of decks when generating the game event, and therefore each turn of a card always has the same probability". Every card is one of 52 with equal chance, whatever has already been dealt. Several things follow directly, and all of them can be worked out on paper.
| Event | Chance | How it is computed |
|---|---|---|
| Any given rank (for example an Ace) | 1 in 13, 7.69% | 4 of 52 cards, on every draw |
| A ten-value card (10, J, Q, K) | 4 in 13, 30.77% | 16 of 52 cards, on every draw |
| Natural blackjack in two cards | 8 in 169, 4.73% | Ace then ten-value, or ten-value then Ace: 2 × (1/13) × (4/13) |
| Player and dealer both dealt blackjack | About 0.22% | (8/169) squared |
| First two cards are the same rank | 1 in 13, 7.69% | The second card matches the first |
| Dealer has blackjack when showing an Ace | 4 in 13, 30.77% | The hole card is a ten-value |
Arithmetic for draws with replacement from 52 cards, the model Stake documents.
The first consequence is for card counting. Counting works on a physical shoe because dealt cards are gone, so the remaining deck drifts rich or poor in tens. With unlimited decks nothing is ever removed. The chance of a ten is 4 in 13 on the first card of a session and on the thousandth, and there is no count to keep.
The second is insurance, which can be priced exactly. The bet costs half the main stake and pays 2:1 if the dealer's hole card is a ten-value. That happens 4 times in 13, so per unit insured the return is (4/13) × 2 minus (9/13) × 1, which is minus 1/13. Insurance costs 7.69% of the amount insured every time it is taken, more than thirteen times the edge on the main hand. "Even money" on a blackjack against an Ace is the same bet under another name.
What the 99.43% assumes
A return figure for blackjack is not a property of the cards alone. It is the return of a player who makes the mathematically best choice on every hand: when to hit, stand, double and split against each dealer card. Under Stake's stated rules (unlimited decks, dealer stands on soft 17, 3:2, double after split allowed, one split, no hitting split aces) that best play returns 99.43%, and Stake's badge is that figure. Every departure from it costs something. Standing on 16 against a ten, never doubling 11, taking insurance: each is a small recurring charge on top of the 0.57%.
The payout on a natural matters more than any single playing decision. A natural arrives about once in 21 hands and pays an extra half unit at 3:2. A table paying 6:5 instead would give up 0.3 of a unit on each of those hands, roughly 1.4% of all money wagered, which more than triples the cost of the game. Stake's Original pays 3:2. It is the first line to check on any other blackjack table, live or software.
At a 0.57% edge the expected cost of a session is 57 cents per $100 wagered with correct play, which is the lowest stated edge among the Stake Originals. Doubles and splits add to the amount wagered, so the cost is on total action, not on the number of hands times the base stake.
How the cards are derived from your seeds
Cards come from the same generator as every Stake Original: HMAC-SHA256 with the server seed as key and clientSeed:nonce:cursor as message, four bytes per number. For cards the number is multiplied by 52 and rounded down to an index into a published list.
CARDS = [ 2 of diamonds, 2 of hearts, 2 of spades, 2 of clubs, 3 of diamonds, … , Ace of spades, Ace of clubs ] (52 entries)
card = CARDS[ floor(float × 52) ]
The list runs through the ranks from 2 up to Ace, and within each rank the suits appear in the order diamonds, hearts, spades, clubs. Index 0 is the two of diamonds and index 51 the Ace of clubs. One hash gives eight cards; when a hand needs more, the cursor is raised and the message hashed again. Stake's implementation page lists Blackjack among the games where the cursor is "unlimited to cover required amount of cards".
The entire sequence of cards for a hand is therefore fixed by the seed pair and the nonce before you act. Your decisions choose how many cards are taken from the sequence; they cannot change what the cards are. Stake's calculation page lists the generated cards for a given seed pair and nonce, which is the place to replay a hand. Two limits apply:
- The documentation describes how each card is generated. It does not set out the order in which cards go to the player, the dealer, a doubled hand or a split hand, so matching a complex hand to the list relies on the order the game displays.
- Our Stake seed checker does not deal blackjack hands. It covers Dice, Limbo, Roulette, Keno, Mines, Plinko and Crash. What it can do for a blackjack session is the commitment check: confirm that the SHA-256 of the revealed server seed equals the hash Stake showed before the hands were played.
Background on what the method does and does not establish: what provably fair gambling proves and the general verifier.
Live-dealer blackjack on Stake
The live tables are supplier games. Stake's help centre says of third-party games that minimum bets mostly range "between $0.1 and $0.2", that maximum bets "vary across games" and are found in each game's menu, and that the per-coin Originals limits do not describe them. Rules are set per table by the studio: number of decks, whether the dealer hits soft 17, what can be doubled and split, and the payout on a natural all vary, and each combination has its own edge. Cards come from a physical shoe on camera, so there is no seed to verify; assurance rests on the studio's licensing and testing. Side bets offered on live tables are priced separately from the main hand and generally carry a much higher edge.
Stake Blackjack against Shuffle, Roobet and Gamdom
| Stake | Shuffle | Roobet | Gamdom | |
|---|---|---|---|---|
| Stated return | 99.43% RTP | "Published 99.48% RTP with correct play" | None stated on the game page | 0.57% house edge after the daily Zero Edge allowance |
| Decks | Unlimited | Unlimited ("infinite decks") | Not stated on the game page | Not stated |
| Natural pays | 3:2 | 3:2 | 3:2 | 3:2 |
| Dealer on soft 17 | Stands | Stands | "Stands on all 17 hands" | Stands |
| Splits | Once | Once | Once | Not stated |
| Side bets | Insurance only in the rules panel | Perfect Pairs and 21+3 | Perfect Pairs and 21+3 | Perfect Pair and 21+3 |
| Limits | Per coin; profit cap e.g. 2,500,000 USDT | $50,000 bet ($10,000 side bet), $2,000,000 win | Shown in the bet panel | $0.01 to $50,000 per seat, up to three seats |
Shuffle: game page 1 Nov 2026, help centre 12 Nov 2026. Roobet: game page 1 Nov 2026. Gamdom: game page 1 Nov 2026 and help centre 12 Nov 2026.
The main-hand rules are close to identical on all four, and so are the stated returns. The practical differences are the side bets and the limits. Shuffle's help centre prices its own side bets at a 2.00% house edge for Perfect Pairs and 3.68% for 21+3, several times the cost of the main hand.
Sources: Stake fairness documentation, implementation and game events (1 Nov 2026); Stake Blackjack game page, rules panel and house-edge guide (1 Nov 2026); Stake help centre, crypto betting limits and third-party game limits (12 Nov 2026). Probabilities and the insurance figure are our arithmetic for draws with replacement.
Licence, KYC and withdrawal terms for Stake are in the Stake review.