Blackjack

Variant played: European · dealer stands on soft 17 · no insurance or surrender · Version 1.0.0

Objective

Get a hand closer to 21 than the dealer's without going over 21.

Setup

1. Use 6 standard decks shuffled on the server.
2. Each player is dealt two cards; the dealer receives one face-up card and one face-down card.
3. Bets are only virtual points/chips with no monetary value.
4. A natural blackjack is an Ace with a 10-value card in the first two cards.

Turn or round flow

1. Players act in order: hit, stand, double, or split when the action is allowed.
2. After all players, the dealer reveals their hole card and draws to 17; they stand on any 17, including soft 17.
3. Each hand is compared separately with the dealer's.

Legal actions and obligations

• Hitting is legal as long as the hand has not gone over 21 and is not closed.
• Standing immediately ends the hand.
• Doubling is allowed only on the first two cards; one extra card is dealt.
• Splitting is allowed when the two cards have the same value; maximum 4 hands.
• After splitting aces, only one card is dealt to each hand and no further draw is allowed; aces may be split only once.
• A 21 made after splitting is not a natural blackjack.

Score

• Normal win: +1 virtual unit; loss: -1; tie: 0.
• Natural blackjack against a dealer non-natural hand: +1.5 virtual units.
• If the player exceeds 21, the hand loses immediately, even if the dealer later exceeds 21.

End of game

• The round ends after all hands have been settled.
• A practice session ends when the player chooses to stop; no balance can be withdrawn or converted.

Locked special cases and variants

• Ace counts as 11 as long as it does not exceed 21, otherwise 1.
• If both the player and dealer have a natural blackjack, it is a tie.
• The five-card rule, insurance, surrender, and side bets are disabled.

Artificial intelligence

The AI uses only its hand, public cards, the allowed history, and the legal actions sent by the server.

• Easy hits below 17 and stands otherwise.
• Normal uses a basic strategy table based on hard/soft totals, pairs, and the dealer's upcard.
• Hard applies this variant's exact basic strategy and chooses splits/doubles without seeing the hole card.