Solitaire, Vegas rules — the only shape solitaire has ever had as a
gambling game. You don't win or lose the deal: the stake buys the deck
outright, and every card you get home to a foundation pays a fifty-second
of the tier's multiple back. Cash the board whenever you like and keep
what you've banked, so a board that has gone dead is a decision rather
than a wall. No undo: the stake is spent the moment the deck is bought,
and an undo would be a way to walk a losing board backwards until it wins.
Three deals, and the two dials are the whole difficulty of Klondike.
Patient draws one with unlimited passes and pays 1.4x, so it takes 38
cards home to get square. Vegas draws three, three times round, 2.2x,
square at 24. Cutthroat draws three and gives you one pass, 3.4x, square
at 16 — most of those boards never clear, and you're ahead long before
they would.
internal/games/klondike is the same pure reducer as the other two, and
Pays() is one function for the same reason hangman's is. Two fuzzers hold
the deck together: no sequence of moves can lose or duplicate a card, and
the board stays well-formed. They earned their keep immediately — the
first thing they caught was a recycle that reversed the waste. It flips as
a block, so the card drawn first comes out first, and reversing it would
have dealt a different game on every pass and quietly broken the seed in
the audit log.
The browser never sees the stock or a face-down card, which here is most
of the deck rather than blackjack's one hole card: a column sends how many
cards are under it, never which.
The table re-renders and animates the difference. Blackjack plays back a
script because a hand only ever grows at one end; solitaire moves runs
from anywhere to anywhere and an auto-finish moves eleven cards at once,
so a script of "append this card there" would be a second engine over here
and it would be the one that's wrong. Instead the board on screen is
always exactly the board the server says exists, and each card is played
from where it just was to where it now is. The events supply only what a
diff can't: where a newly-revealed card came from, and what the board is
worth.
The rules are mirrored in JS on purpose, and only to light up the columns
a held card can go to. Being shown where a card goes is the game teaching
you; being told no after you commit is the game scolding you. The server
still decides, and a disagreement snaps the board back to what it says.
Two things came out into the open rather than being copied, which is the
rule this room runs on: casino-cards.js (the deck — faces, pips, the flip)
and PeteFX.spot() (the pile of chips and the number under it, which now
owns the rule that the number is a readout of the pile). Blackjack uses
both.
Not yet driven in a browser.
The table dealt cards but settled money by editing a number. So the felt got
the two things it was missing: a bet spot in front of you, and the house's rack
beside the shoe. Every chip is now always travelling between one of those and
the other.
You build a bet by throwing chips onto the spot — the chip you clicked is the
chip that flies. The stake sits there through the hand. The house pays out of
its rack into the spot, and the pile is then swept back to your stack. A loss
goes to the rack and does not come back.
Two rules hold it together. The number under the pile is a readout of the pile,
never the other way round: the bet starts at nothing rather than at a default
nobody put down, and a settled hand leaves your stake back up on the spot,
because otherwise the panel prints "your bet: 300" over an empty circle. And
the chip bar does not move until the chips that justify it have landed — a
counter that pays you before the dealer turns over is a counter that has told
you the ending.
casino-fx.js is the engine underneath: chips fly on an arc, out of a fixed
overlay so no container clips one crossing from a button to the felt. It knows
nothing about blackjack.
Also: cards land with weight and a degree or two of tilt, so a hand looks dealt
rather than typeset; the dealer takes a beat before drawing out; and a natural
gets confetti, which is the only thing in the room that does.
Driven in a real browser, which is the only way to review an animation — and
which is what caught the verdict pill rendering white on white in a dark room,
a chip rack sitting on top of the dealer, and Hit being offered over a table
that was still being paid out. devcasino_test.go is that harness, kept.