Blackjack — How to play & pay table

Everything about the game: how it plays, what each combination pays, the RTP, and how every round can be verified on-chain.

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Blackjack

21 points — Hit, Stand, Double, Surrender

House Edge: 0.08–2%

On-chain Blackjack — classic 21, dealt to European (No Hole Card) rules. You play the dealer, and a provably-fair VRF (Chainlink on EVM, Switchboard on Solana) draws every card from an 8-deck shoe. The deal goes: one card to you, one up-card to the dealer, then a second card to you. You finish your hand first — Hit, Stand, Double or Surrender — and only after that does the dealer take its second card and draw on. The dealer stands on a hard 17 but hits a soft 17 (the H17 rule), and a natural blackjack pays 3 to 2.

European rules (no hole card)

Why this table deals European: on a public blockchain, a face-down card is not actually hidden. Every card here is derived from a VRF value that must be revealed for you to see your own hand — so an American-style hole card, dealt at that same moment from that same value, could be recomputed by anyone the instant the deal was revealed. “Face-down” on-chain would be theatre. So the dealer's second card is never drawn while a decision of yours could still depend on it. It arrives only once nothing you do can be affected by it: at the end of the round, from randomness committed after you have finished, or derived from the value that ended your turn — or immediately, in the single case where your first two cards make 21 and the hand resolves on the spot with no decision left to make. While you still have a choice to make, the dealer's remaining cards have not been drawn from anything yet — there is nothing to leak, rather than something merely hidden. The principle is not “we hide the card”, it is “we never draw a card while a decision could still exploit it”, and it governs the whole table: the second hand of a split likewise waits for fresh randomness instead of taking its card from the split value you have already seen. Keeping the dealer's card genuinely unknown while every card stays publicly checkable is the honest way to do it — and it is exactly how European casinos deal.

What that rule costs you, stated plainly: because the dealer's second card lands last, money you add in the middle of a hand is exposed to it. If you Double or Split and the dealer then completes a natural blackjack, that extra stake goes down with the hand. Only a natural against a natural pushes. The dealer only draws out its hand when a hand of yours is still standing to be compared — bust or surrender and the round settles on the spot, with the dealer never drawing at all.

European rule sets are a house-wide choice here, and roulette is the clearest place that choice pays the player: the wheel here is single-zero, 37 pockets, so the house takes exactly 1/37 = 2.70% on every bet type, where an American double-zero wheel takes 2/38 = 5.26% on the same bets — nearly twice as much, and a straight gain in RTP for the player. None of this has to be taken on trust: the contracts ship as verified builds, so the on-chain bytecode can be checked against the source, and every card can be recomputed from its published VRF value.

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Fairness

A provably-fair VRF per card draw — Chainlink on EVM, Switchboard on Solana. Every seed stored permanently on-chain.

Randomness by: Chainlink VRF · SwitchboardContract operated by: DODEN.IO

Frequently asked questions

How does Blackjack work?: You get 2 cards; the dealer shows only 1 (the up-card) — this table runs European no-hole-card rules, so the dealer draws the rest of its hand at the END of the round. The reason is practical: on a public chain, a hole card dealt up front would be recomputable from the same VRF value you must be shown to see your own cards, so it is drawn later instead — once no decision of yours can exploit it. You pick Hit, Stand, Double (double the stake, take exactly one card, then stand) or Surrender (forfeit for a 50% refund — first action only); and Split when your first two cards are the same rank — Split is available on BOTH chains. The hand closest to 21 without busting wins. Cards come from an 8-deck shoe (416 cards).
Natural BlackJack payout?: A natural (A + 10/J/Q/K on the first two cards) = 2.5x, i.e. it pays 3 to 2. Regular win = 2x. Push = 1x (stake returned). Surrender = 0.5x. Loss = 0. All figures are GROSS — the returned stake is included. Note: a 21 built from three or more cards, a 21 after doubling, and a 21 on a split hand are NOT naturals — they pay as an ordinary 2x win.
What happens to my 21 if the dealer has blackjack?: A dealer natural beats every hand that is not itself a natural — including a 21 you drew to. Only natural versus natural pushes. Because this table deals no hole card, the dealer's second card is revealed only at the end of the round, so the extra money you put up on a Double or a Split carries that risk too. This is the standard international rule for no-hole-card dealing, and it is enforced by the on-chain program.
When does the dealer stop drawing?: The dealer stands on a hard 17 but HITS a soft 17 (a 17 still counting an Ace as 11) — the H17 rule. It is a constant in the program and is identical on both chains.
When to Double?: Basic strategy: Double when your hand totals 10 or 11 (high chance of hitting 20-21). Split (available on both chains) follows these rules: doubling after a split is allowed, you may split up to 4 hands, and split Aces receive exactly one card each and then stand.
What if I disconnect or walk away mid-hand?: Every action has a countdown: about 4 minutes on Solana, and 200 blocks on Arbitrum (~40 minutes — those are L1 blocks, not L2). Once it expires ANYONE can call the cleanup door. A hand on its first two cards that has not doubled AND did not come from a split is forced to SURRENDER — half your stake back. A hand that has already drawn — and EVERY hand created by a split, even while it still holds two cards — is forced to STAND on Arbitrum, and the dealer still plays out, so you can still win if your hand is better; on Solana that hand is scored a LOSS of the whole stake. After a split each hand carries its own window. This is not a penalty for its own sake — a hand left open locks bankroll capital indefinitely, so there has to be an exit that needs no privileged key. Finish your hand; do not close the tab mid-round.
Are there bet limits?: Minimum bet is 10 USDT. This page caps the input at 1,000 USDT; the REAL ceiling is the bankroll's Kelly fraction of its live liquidity, so whichever is lower applies — and that is what keeps every winning hand fully payable.