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Boulevard 21 · a card game in progress

A blackjack game, tuned by thousands of simulated nights.

It’s 1931: five dollars, seven nights, and a hundred-dollar debt to the house. Each dealer plays by a rule of their own.

I play it and approve every rule; AI models write and review the code. In active development, not released.

See how a night works ↓ See how it’s tested ↓
The Boulevard 21 title screen: a rainy 1931 street at night, a man walking toward the lit door of the Cardinal Club, and the words seven nights, one hundred dollars, one table.
A real screen from the game: the title, on the street outside the first club.
How it’s built 355 rules tests and 110,000 simulated nights check every rule change. A rule ships only if a careful player can still win, and the night still gets harder.
On this page · 5 sections · 3 min read
Why I’m making it

Blackjack you already know. A house that plays back.

Most card games either teach you nothing new or bury you in rules. I wanted one a blackjack player can sit down at in a minute, where the depth comes from the dealers: one always opens with a ten, another can swap a card with you under a posted rule.

Each night you choose a table, try to win its target in a set number of hands, and decide whether to walk out with what you have. Never more than seven things to understand at one table is a written rule of the project.

  1. The floor: three dealers, Mr. Vale, Mr. Ten, and Mara Vex, each with a respect rating, and Mr. Vale’s table selected with its target and house rule.
    1. Pick a table. Each dealer has a target and a rule.
  2. A hand in play at the felt, with the player’s charms listed on the right and the dealer’s up card showing.
    2. Play the hand. Charms add a small edge you can see.
  3. The end of a run: a panel reading the debt is paid, with each night’s result listed.
    3. Pay the house. Seven nights to clear the debt.
How it’s tested

Every rule change gets played thousands of times before I play it.

The rules run on their own, without the screens, so a computer can play them fast. Each check plays 2,000 nights for each of 11 playing styles, from careful to reckless, at each of 5 difficulty levels. The question is the same one I ask of an ad report: does the number mean what it seems to?

A careful player should win most tables early and about half at the end. Tables a careful player clears, by difficulty, across 2,000 simulated nights each.
What the simulations caught An early version looked reasonable on paper. The simulations said otherwise: day one failed in 61–71% of runs, even for aggressive players, and only 5–7% ever paid off the debt. That finding drove the retune.
The game, screen by screen

A night makes more sense when you can see every beat.

Real screens from the current build, in order. Select any screen to see it larger.

The opening scene: a collector in a dark back room explaining the debt.
The debt. A collector explains what you owe.
The floor with three dealers to choose from.
The floor. Three dealers, three rules, one night.
A hand in play with the player’s charms listed.
The hand. Hit, stand, or double, as in any blackjack.
A winning hand with each charm’s contribution added up in a tally.
The payout. Every charm’s share is added up in plain view.
A moment at the table: the dealer offers a fresh deck that pays more on blackjack for three hands.
A moment. The house offers a deal. You can say no.
The bar between tables, where the bartender offers three charms.
The bar. Between tables, spend tonight’s cash on a charm.
The journal’s dealer page: Mr. Vale’s rules, tells, and how his game changes as respect grows.
The journal. What you’ve learned about each dealer, written down.
The journal’s rules page, explaining tonight’s target with a dial and a glass that empties.
The rules page. One picture per idea, not a wall of text.
The debt is paid: the end-of-run summary.
The debt is paid. Seven nights, settled.
A membership card for the Cardinal Club, earned by finishing the run.
The card. Membership opens the next part of the boulevard.

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What it took

The game is the smaller half. The record of it is the rest.

Problems logged
342 problems found in play and review, each numbered, with its evidence and how the fix was checked.
Decisions logged
280 decisions written down with the reason, so a later change can’t quietly undo an earlier one.
Rules of work
86 written standards, from the seven-things rule to “every picture must fit the world, or it is redone.”
Screens checked
43 reference screens are compared after every change, so a fix in one place can’t break the look of another.
How long
Started in late September 2026; 208 saved changes by mid-October.
Where it stands

Playable and tested. Not yet played by strangers.

The rules are measured. Whether it feels good to someone new is still an open question.

Today A full first club Seven nights, three dealers and the owner’s table, the bar, the journal, and an ending, on my own computer.
Next Outside players A written playtest plan is ready. No one outside the project has played it yet.
Not yet A release No claims about sales, players, or growth. It ships when the playtests say it’s ready.
Say hello

Up for a playtest someday?

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Keep going
Back to the start All five projects Marketing work and things I built for fun. See the projects → Or meet me About Juan The person, background, and life behind the work. See the About page →