Rules

These are Classic Blackjack baseline rules. Poker Head's builds and environment, and J-54's Table, override the applicable parts.

Goal

At the Classic Table you bring 40–100 chips from your vault and win the run at 4 times what you brought. (Without a vault, for example the agent CLI, a run starts with 100 chips and the goal is 300.) You lose when you run out of chips or can no longer place a legal bet.

Betting

Each round you bet a whole number from 5 up to 0.5 × your bankroll, rounded down. You can never go all-in.
Before betting you may visit the shop.

Card values

2–10 are worth their face value; J, Q and K are worth 10.
An Ace counts high, but drops by 10 whenever the hand would otherwise bust. A fixed-value environment rule can disable this choice; read its declared effect.
Chaos rules change card values before the total is summed. The total shown on screen always includes them: trust it over mental arithmetic.

A round

You and the dealer get two cards each; the dealer's second card is face down (the hole card).
Naturals settle before player actions: an original Ace plus a ten-value card pays 3:2, rounded down. The dealer's natural ends the round before you act; two naturals push.
In legacy Chaos compatibility, otherwise the Chaos AI acts once. A rule can immediately bust a starting hand; Reverse Bust changes a player bust to a push. A hand changed to 21 by a rule does not gain the natural payout.
Your turn: hit, stand, double or surrender, or use an item.
The dealer reveals the hole card and draws until reaching 17 or more.
Settlement: win +bet, lose -bet, push 0.

Double and surrender

Both are allowed only on your first decision (exactly two cards). Using an item does not count as a decision.

Double (enabled: yes): the bet doubles, you get exactly one card, then you stand.
Surrender (enabled: yes): you give up the hand and get half the bet back, rounded in the house's favour.

Bust

Going over the bust limit (21, unless a chaos rule changes it) on your own hit or double ends the round at once; the dealer does not draw.