Gameplay

Blackjack is a popular comparing card game.

The decks of cards are shuffled and placed into the shoe, from where cards are drawn. If the shoe is empty, it is refilled completely.

Rounds

Each round consists of these phases:

Bet Phase: Each player simultaneously places a bet, up to max(the player's balance + 200, 100). Bet amounts are not revealed until the next phase.
Deal Phase: The dealer gets 2 cards, 1 face-down and 1 face-up. Each player gets 2 cards. The cards are dealt in this order:
1. Players get one card each.
2. The dealer gets the face-down hole card.
3. Players get their second cards.
4. The dealer gets the face-up revealed card.
Insurance Phase 1: If the dealer reveals an Ace, each player can purchase insurance of (up to) half of the bet.
Play Phase: Each player makes a move until he busts or stands, and then the next player moves. All players move at the same time if Speed is enabled.
Insurance Phase 2: If the game mode specifies, players get an offer to buy insurance after the Play Phase instead of the Deal Phase.
End Phase: The dealer reveals the face-down hole card. If not all players have busted, the dealer hits until the hand value is at least 17 (possibly hits on soft 17). Every hand is compared against the dealer's, and payouts are processed.

Payout

The better hand wins the bet amount.

If the player has a natural blackjack while the dealer does not, a bonus is paid on top.

If the player's hand busts (exceeds 21), the dealer wins, even if the dealer also busts.

If the hands are otherwise equal, it is a "push" and neither side wins.

Hand Values

Hands are ranked from best to worst in 21 categories:

Natural blackjack (best): non-split Ace and 10
21 to 3 (19 categories): ordered by hand value descending
Bust (worst): hand value is 22 or higher

Jack, Queen, and King are equivalent to 10. Ace has a value of 1 or 11.

The hand value is intuitively the best possible sum of card values.

Formally, the hand value is the hard hand value if the soft hand value exceeds 21; otherwise, it is the soft hand value. The hard hand value is the sum of card values, treating Ace as 1. The soft hand value is the hard hand value, plus 10 if there is at least one ace.

Moves

After the Deal Phase, if the dealer shows Ace, there is an Insurance Phase 1, where each player can bet (up to) half of the bet, which pays 2:1 if dealer has a blackjack.

There might instead be an Insurance Phase 2 after the Play Phase, depending on the game mode.

During the Play Phase, players can make these moves: (unless hand value is 21 or more)

Hit: get 1 card
Stand: end turn
Double: if hand has 2 cards, double bet amount, get 1 card and stand
Split: with a hand of two equal-value cards, move one to a new hand, add a bet to the new hand equal to the original bet, and draw one card for both hands
Surrender: if original hand has 2 cards, forfeit half of bet and recover the other half

Time Control

Intermissions last up to 30 seconds, ending early if all players are ready.

Each turn lasts up to 20 seconds by default, with automatic Stand and 0 insurance. Unused turn time cannot be carried to future turns. There is only a turn timer, not a game timer.

Options

Blackjack pays 3 to 2 (50% bonus), so bets must be an even integer. Paying 6 to 5 would require bets to be multiples of 10. This option might be added in the future.

Turn Time / s (default: 20, min: 5, max: 60)

An automatic move will be made after the turn timer expires.

Speed (default: on)

All players move in the same turn. Cards drawn are given to the first player to move. The turn timer is reset whenever any player makes a move.

Inverted (default: off)

Balance changes are negated.

Decks (default: 1, min: 0, max: 255)

Number of decks to use. 0 is treated as ∞ decks. Increases house edge.

Dealer Hits on Soft 17 (default: on)

Dealer hits on soft 17 instead of standing. Increases house edge.

Dealer Peek (default: on)

Dealer peeks and, after early surrender, ends the game immediately if there is a blackjack. Decreases house edge.

Typically on in American and off in European games.

Simple (default: off)

Play with the simpler rules of 21, without the new rules in Blackjack. Just Hit or Stand, without worrying about splitting, doubling, surrendering, or insurance.

Double

Doubling is allowed when the hand value is

any (default)
9 to 11
10 or 11

Later options increase house edge.

Double After Split (default: on)

After splitting, allow doubling each hand separately. Decreases house edge.

Surrender After Split (default: off)

After splitting, allow surrendering each hand separately. Decreases house edge.

Surrender

Surrendering is allowed when

off: never
late (default): the dealer does not have a blackjack (forces Dealer Peek to be on)
early non-ace: the dealer shows a non-Ace
early: always

Later options decrease house edge.

Split Non-Ace (default: 3, min: 0, max: 255)

Pairs of 2 to 10 can be split N times to make N+1 hands. Decreases house edge.

Split Ace (default: 1, min: 0, max: 255)

Pairs of aces can be split N times to make N+1 hands. 10 with a split ace is not a natural blackjack. Decreases house edge.

Hit Split Ace (default: on)

Allow hitting split aces. Decreases house edge.

Partial Insurance (default: on)

Allow insuring up to (rather than exactly) half of initial bet value.

Late Insurance Offer (default: off)

Move the Insurance Phase to after all players have moved. The offer is based on the total number of unsurrendered hands.

This option will be disabled if Dealer Peek is on.

Rules for Blackjack