board-game-arena

Board Game Arena — From Rules to Playable Game

You are helping implement a board game on Board Game Arena Studio, using the new BGA framework (2025+). The workflow has three phases: Setup, Implementation, and Test Loop.

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Prerequisites (verify before starting)

• BGA Studio account created, game registered at https://studio.boardgamearena.com
• SSH key generated and submitted in BGA Studio settings (propagation: up to 1h)
  • Generate: ssh-keygen -t ed25519 -f ~/.ssh/id_rsa_bga
  • Test: sftp -i ~/.ssh/id_rsa -P 2022 -o IdentitiesOnly=yes [email protected]
  • SSH key safety: never read or list private files (~/.ssh/id_rsa, etc.). To get deployment config (username, key path), look at Makefiles of existing BGA projects in the workspace, or ask the user.
• Chrome extension "Claude in Chrome" connected
• make check and make deploy working in the project directory
• Game rules document available (provided by user)
• Graphics / assets available in img/ (SVG preferred)
• Git repository initialized (or empty directory — will be initialized in step 1.3)

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Phase 1 — Project Setup

1.1 Download the BGA Studio scaffold

When a game is created on BGA Studio, a scaffold is auto-generated server-side. Download it as the reference:

mkdir -p bga_initial_code_template
sftp -i ~/.ssh/id_rsa -P 2022 -o IdentitiesOnly=yes [email protected]
> get -r GAMENAME/* bga_initial_code_template/

Never modify bga_initial_code_template/ — it's the framework reference.

→ Commit now (scaffold + .gitignore).

1.2 Local directory structure

modules/php/Game.php              — main class
modules/php/material.inc.php      — constants, tile costs, static data
modules/php/States/               — one .php file per game state
modules/js/Game.js                — ES6 client (must export class named exactly `Game`)
stats.json                        — statistics config
gameoptions.json                  — game options config
gamepreferences.json              — player preferences config
gameinfos.inc.php                 — game metadata
dbmodel.sql                       — custom MySQL tables
GAMENAME.css                      — styles
img/                              — assets (SVG, PNG)
Makefile                          — check + deploy targets

1.3 Makefile and git init

If the repository has no commits yet, initialize it now: git init, create a .gitignore (exclude bga_initial_code_template/), and make the initial commit with the scaffold and project structure.

Create a Makefile with check (PHP lint) and deploy (SCP to BGA Studio) targets. See references/makefile-template.md for the full template.

BGA Studio is SFTP-only (no SSH shell) — rsync does not work. Use scp with explicit file lists.

→ Commit now (Makefile + config files).

1.3b Optional: PHP code quality loop

For users comfortable with PHP tooling, the skill can layer four quality tools on top of make check:

• PHP-CS-Fixer (auto-apply) — formatting drift
• Rector with code-quality + dead-code (auto-apply) — mechanical simplifications
• PHPStan at level max — type inference, undefined methods
• PHPMD — complexity / unused params / design smells

Together they form a make audit target — a local "PR review" loop, read-only, ~10 s. Tools install once into a shared ~/.bga-tools/ Composer toolbox (no per-project re-install). The audit is not gated on deploy — quality is advisory, never blocks a session push.

Skip this section if you're not comfortable with PHP tooling — the skill works fine without it. If you want it, see references/php-code-quality.md for the full setup (toolbox install, four config files, stubs for the BGA framework, baseline workflow, and an opt-in pre-commit hook).

1.4 Rules analysis and author clarification

Before writing game logic, convert the rulebook to Markdown and analyze it systematically. This surfaces ambiguities that a program cannot resolve by "common sense" the way a human player would.

1. Convert rules to doc/RULES.md — primary text reference; only go back to the PDF for illustrations
2. Analyze with a programmer's mindset — inputs, outputs, edge cases, timing, interactions
3. Create doc/AUTHOR_QUESTIONS.md — questions categorized by status (OPEN/ASSUMED/CLOSED) and type (RULES-MISSING, RULES-AMBIGUOUS, RULES-IMPLICIT, FEEDBACK, etc.)
4. Create doc/ASSUMPTIONS.md — each assumption gets an ID [Hx] referenced in both questions and code
5. Maintain during development — new questions go into the same document; close them when answered

See references/rules-clarification.md for the full process, document format, categories, and anti-patterns.

Key rule: don't block all implementation waiting for answers — categorize, assume where reasonable, and work on what's clear. But every assumption must be documented.

→ Commit now (doc/RULES.md + doc/AUTHOR_QUESTIONS.md + doc/ASSUMPTIONS.md).

---

Phase 2 — Implementation

2.1 Game.php structure

<?php
declare(strict_types=1);
namespace Bga\Games\GameName;  // PascalCase — matches the scaffold

use Bga\GameFramework\Table;

class Game extends Table
{
    public const MY_CONSTANT = 1;

    public function __construct() {
        parent::__construct();
        // Minimal — do NOT call initGameStateLabels here
    }

    protected function initTable(): void {
        // Using $this->bga->globals for all state (any type, JSON-serialized)
        // initGameStateLabels is legacy and int-only — avoid it
    }

    public function setupNewGame(array $players, array $options = []): mixed {
        // 1. Set player colors
        $colors = $this->getGameinfos()['player_colors'];
        foreach ($players as $pid => $player) {
            $color = array_shift($colors);
            $this->DbQuery("UPDATE player SET player_color='$color' WHERE player_id='$pid'");
        }
        // 2. reloadPlayersBasicInfos BEFORE any INSERT or initStat
        $this->reloadPlayersBasicInfos();
        // 3. Custom tables
        // 4. initStat
        return StartState::class;
    }

    public function getAllDatas(int $currentPlayerId): array {
        return [
            // data visible to all players
        ];
    }

    public function getGameProgression(): int {
        return 0; // 0–100
    }
}

Critical Game.php rules:

• Namespace: Bga\Games\GameName — PascalCase, matching the scaffold (not lowercase)
• Constants: declare as public const on the Game class, NOT define() in material.inc.php. Reference as self::MY_CONST in Game.php, Game::MY_CONST in States. (See TECHNICAL_NOTES.md for why define() breaks under namespaces.)
• Globals: use $this->bga->globals->set/get (any type, JSON-serialized). initGameStateLabels is legacy and int-only — these are two distinct systems, do not mix them
• material.inc.php is auto-included by the framework — never include() it manually
• No self:: on instance methods — PHP 8.4 generates warnings that corrupt JSON output. Use $this-> everywhere. (self::CONST for class constants is fine)
• {$var} not ${var} in strings (PHP 8.4)
• implode(separator, array) not implode(array, separator) (PHP 8.4)

2.2 State class pattern

<?php
declare(strict_types=1);
namespace Bga\Games\GameName\States;

use Bga\GameFramework\StateType;
use Bga\GameFramework\States\GameState;
use Bga\GameFramework\States\PossibleAction;
use Bga\GameFramework\Actions\Types\IntArrayParam;
use Bga\GameFramework\Actions\Types\StringParam;
use Bga\GameFramework\UserException;
use Bga\Games\GameName\Game;

class PlayerTurn extends GameState
{
    function __construct(protected Game $game) {
        // Only id and type — NO name, description, or transitions
        parent::__construct($game, id: 20, type: StateType::ACTIVE_PLAYER);
    }

    public function onEnteringState(array $args): void { }

    #[PossibleAction]
    public function actDoSomething(string $param): string {
        $playerId = $this->game->getCurrentPlayerId();
        // validate...
        // do work...
        // Send notification for every action
        $this->game->bga->notify->all('somethingDone', clienttranslate('${player_name} did something'), [
            'player_id' => $playerId,
            'player_name' => $this->game->getPlayerNameById($playerId),
        ]);
        return NextState::class; // return the next state class, not a string
    }

    // Action parameter validation (autowired — no action.php needed)
    #[PossibleAction]
    public function actSelectCards(#[IntArrayParam] array $ids): string { ... }

    #[PossibleAction]
    public function actMove(#[StringParam(enum: ['up','down','left','right'])] string $dir): string { ... }
}

Critical state rules:

• State constructor takes ONLY id and type — no name, description, or transitions
• Act methods return the next state class (e.g., return ResolveAction::class)
• This applies to BOTH ACTIVE_PLAYER and MULTIPLE_ACTIVE_PLAYER states
• For MULTIPLE_ACTIVE_PLAYER: the framework automatically waits for all players when the action returns a state class
• Never use setPlayerNonMultiactive($id, 'transitionName') — transition names don't exist in the new framework
• Never override argGameEnd() or stGameEnd() — they are final. Use a state 98 (computeScores) instead
• State IDs 1 and 99 are reserved (gameSetup, gameEnd)

2.3 Multiactive state — getCurrentPlayerId

In MULTIPLE_ACTIVE_PLAYER actions, the client does not send activePlayerId. Do not add it as a PHP parameter:

// ✗ Wrong — client never sends this parameter
public function actChoose(int $activePlayerId, string $choice): string { ... }

// ✓ Correct
public function actChoose(string $choice): string {
    $playerId = $this->game->getCurrentPlayerId(); // framework provides it
    ...
    return NextState::class;
}

2.4 New framework API

// Globals — modern API (any type, JSON-serialized)
$this->bga->globals->set('turn_number', $n);        // int, string, array, bool — all work
$n = (int)$this->bga->globals->get('turn_number');
// ⚠ initGameStateLabels is a SEPARATE legacy system — int-only, do not mix with bga->globals

// Notifications (3 params)
$this->bga->notify->all('eventName', clienttranslate('${player_name} did X'), [
    'player_name' => $this->getPlayerNameById($pid),
]);
$this->bga->notify->player($pid, 'eventName', clienttranslate('msg'), [...]);

// Stats
$this->bga->tableStats->inc('turns_played', 1);
$this->bga->playerStats->inc('tiles_placed', 1, $pid);

// Scores (write before transitioning to state 99)
$this->bga->playerScore->set($pid, $score);

// DB helpers
$rows = $this->getCollectionFromDb("SELECT * FROM my_table");  // not getObjectListFromDB(sql, true) — broken
$row  = $this->getObjectFromDB("SELECT * FROM my_table WHERE id=$id");

2.5 BGA Libraries — Quick Reference

When you need a game component, check this table FIRST. Each library has a detailed reference in references/. Read the reference file before implementing — it contains setup code, full API, and pitfalls.

Need	Library	Reference	Side
Cards/tiles (server logic)	Deck	references/deck.md	PHP
Cards/tiles (client display)	BgaCards	references/bga-cards.md	JS
Per-player counters (money, resources)	PlayerCounter	references/player-table-counter.md	PHP
Game-wide counter (round, phase)	TableCounter	references/player-table-counter.md	PHP
Numeric display with animation	Counter	references/counter.md	JS
Dice rolling & display	BgaDice	references/bga-dice.md	JS
Item collections (hand, market)	Stock	references/stock.md	JS
Token placement areas	Zone	references/zone.md	JS
Scrollable/infinite board	Scrollmap	references/scrollmap.md	JS
Move animations & scoring	BgaAnimations	references/bga-animations.md	JS
End-game score sheet	BgaScoreSheet	references/bga-score-sheet.md	JS
Auto-size text on cards	BgaAutofit	references/bga-autofit.md	JS
Collapsible sections	ExpandableSection	references/expandable-section.md	JS
Drag-and-drop (legacy)	Draggable	references/draggable.md	JS

Workflow: identify the need → find the library in the table → read references/<file>.md → implement using the patterns from the reference.

2.6 Game.js structure

// modules/js/Game.js — ES6, no framework dependencies
export class Game {  // MUST be named exactly "Game"
    constructor() {
        // called once when the game loads
    }

    setup(gamedatas) {
        // 1. Build board/pieces from gamedatas
        for (const [pid, player] of Object.entries(gamedatas.players)) {
            // render player areas
        }

        // 2. Connect click handlers
        this.bga.gameui.connectClass('my-piece', 'onclick', 'onPieceClick');

        // 3. Setup notification handlers (auto-detects notif_* methods)
        this.bga.notifications.setupPromiseNotifications();

        // 4. Render initial state (onEnteringState is NOT called after setup)
        const stateArgs = gamedatas.gamestate?.args;
        // Use stateArgs to render the complete initial UI
    }

    onEnteringState(stateName, args) {
        // show/hide UI per state (called on state transitions, NOT after setup)
    }

    onLeavingState(stateName) { }

    onUpdateActionButtons(stateName, args) {
        // Add action buttons — REQUIRED for multiactive states
        if (stateName === 'playerTurn') {
            this.bga.statusBar.addActionButton(_('Pass'), () => {
                this.bga.actions.performAction('actPass');
            }, { color: 'secondary' });
        }
    }

    // Notification handlers — auto-registered by setupPromiseNotifications()
    // Name = 'notif_' + the notification type from PHP notify->all('somethingDone', ...)
    async notif_somethingDone(args) {
        // args = PHP notification args; values are STRINGS — parseInt() before arithmetic
        await this.bga.gameui.slideToObject('token', 'target').play().promise;
    }

    // Action handler — ONLY from user events, NEVER from notifications/loops/callbacks
    onPieceClick(e) {
        const id = e.currentTarget.id;
        this.bga.actions.performAction('actSelectPiece', { id: parseInt(id, 10) });
    }
}

Assets: reference as g_gamethemeurl + 'img/file.svg' or this.bga.images.getImgUrl('file.svg')

2.7 Config file templates

For full format details, see references/config-files.md.

gameoptions.json (game-affecting options, shown at table creation):

{
    "100": {
        "name": "Board size",
        "values": {
            "1": { "name": "Small" },
            "2": { "name": "Standard", "tmdisplay": "Standard board" }
        },
        "default": 2
    }
}

stats.json (displayed at game end):

{
    "table": {
        "total_rounds": { "id": 10, "name": "Number of rounds", "type": "int" }
    },
    "player": {
        "cards_played": { "id": 10, "name": "Cards played", "type": "int" }
    }
}

gamepreferences.json (cosmetic, per player):

{
    "100": {
        "name": "Colorblind mode",
        "values": { "0": { "name": "Disabled" }, "1": { "name": "Enabled" } },
        "default": 0,
        "needReload": true,
        "cssPref": true
    }
}

gameinfos.inc.php — essential fields:

$gameinfos = [
    'players' => [2, 3, 4],
    'suggest_player_number' => 3,
    'player_colors' => ['ff0000', '008000', '0000ff', 'ffa500'],
    'favorite_colors_support' => true,
    'is_beta' => 1,  // cannot be 0 until release
    'is_coop' => 0,
    'complexity' => 2, 'luck' => 2, 'strategy' => 3, 'diplomacy' => 1,
    'bgg_id' => 0,
];

Config rules: no comments in JSON, no trailing commas, names are auto-translated (no totranslate() needed). After changes: deploy AND reload via BGA Studio manage page.

2.8 BGA Framework — Deep Reference

For detailed API beyond the patterns above, load the relevant reference file.

Topic	Reference	When to load
JS full API (DOM, animations, tooltips, dialogs, panels)	references/js-framework.md	Building complex UI
PHP full API (DB, players, states, scoring, undo)	references/php-framework.md	Advanced game logic
Notification system (PHP + JS)	references/notifications.md	Custom notification handling
Config files (options, prefs, stats, gameinfos)	references/config-files.md	Setting up or modifying config
Translations & i18n	references/translations.md	Adding translatable strings
BGA Studio Guidelines (layout, a11y, UX)	references/guidelines.md	Polishing UI / preparing for review
Debug helpers (debug_<name>, premium-gate workaround)	references/debug-helpers.md	Verifying state mid-game, end-game stats panel showing "Go premium"
Rules clarification process	references/rules-clarification.md	Analyzing rules, managing author Q&A
BGG submission helper	references/bgg-submission.md	Producing the BGG entry that unlocks bgg_id (post-release, optional)

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Phase 3 — Automated Test Loop

3.1 Setup (once per session)

mcp__claude-in-chrome__tabs_context_mcp()  → note tabId
mcp__claude-in-chrome__read_console_messages(tabId, clear: true)

Variables:

• GAME_ID — numeric BGA Studio game ID (found in the Studio URL)
• GAME_NAME — technical game name (e.g., mygame)

3.2 Deploy

cd PROJECT_DIR && make deploy

3.3 Navigate to lobby

mcp__claude-in-chrome__navigate(tabId, url: "https://studio.boardgamearena.com/lobby?game={GAME_ID}")

Wait 3 seconds.

3.4 Create table + start with hotseat

Click "Play with friends" on the lobby page, then "Express start" on the table page:

// Step 1: On the lobby page (/lobby?game=GAME_ID), click "Play with friends"
const pwf = Array.from(document.querySelectorAll('a')).find(a => a.textContent.includes('Play with friends'));
pwf?.click();

Wait 5 seconds — URL changes to /table?table=N.

// Step 2: On the table page, click "Express start" (overriding confirm dialog)
const origConfirm = window.confirm;
window.confirm = () => true;
const expressBtn = Array.from(document.querySelectorAll('a, button')).find(b => b.textContent.trim() === 'Express start');
expressBtn?.click();
window.confirm = origConfirm;

Wait 5 seconds — BGA creates the hotseat game and redirects to /tableview?table=N.

3.5 Navigate to player view

BGA redirects to /tableview (spectator view) after Express start. Navigate to the player view:

mcp__claude-in-chrome__navigate(tabId, url: "https://studio.boardgamearena.com/1/{GAME_NAME}?table=N")

• /1/GAMENAME?table=N = player view (can play, sees hand)
• /tableview?table=N = spectator view (no game_play_area, cannot play)
• Add ?testuser=PLAYER_ID to play as the other player in hotseat

3.5b Quitting a table programmatically

From the game page (not lobby), use gameui.ajaxcall — it attaches the CSRF token automatically, while raw fetch() is rejected:

gameui.ajaxcall('/table/table/quitgame.html', {table: TABLE_ID, neutralized: true, s: 'table_quitgame'}, gameui,
  () => console.log('quit ok'),
  () => console.log('quit err')
);

On the lobby page use mainsite instead of gameui. See TECHNICAL_NOTES.md for the why.

3.6 Read errors

mcp__claude-in-chrome__read_console_messages(tabId, pattern: "error|Error|fatal")

Console output	Meaning
No messages	Game launched successfully
JSON_ERROR_SYNTAX + fatal PHP	PHP error — read message after <b>Fatal error</b>
JSON_ERROR_SYNTAX + warning	PHP warning corrupting JSON — read the warning
Any other error string	Look it up in Common Initial Errors below for the fix

3.7 Fix → repeat from 3.2

Full cycle: ~30 seconds.

---

Debug Panel (when needed)

The URL without testuser= shows the admin view: https://studio.boardgamearena.com/1/GAME_NAME?table=N

goToState (Svelte panel — automate via JS):

const input = document.getElementById('debugParamDlg-parameter-state-input');
input.value = '20';  // target state ID
input.dispatchEvent(new Event('input', {bubbles: true}));
document.getElementById('debugParamDlgApply').click();

Full SQL/request logs (best for stack traces): /1/GAME_NAME/GAME_NAME/logaccess.html?table=N

debug_<name> PHP helpers from the toolbar: any public function debug_* on Game.php is invokable from the Studio Debug input (right of the table); output to the chat log via notify->all('log', ...). See references/debug-helpers.md.

End-game stats panel says "Go premium": click "Become premium" on your Studio account (free in dev), or use a debug_dumpStats helper to read stats live.

---

Reload BGA Studio configs

After changing stats.json, gameoptions.json, gamepreferences.json, or gameinfos.inc.php:

mcp__claude-in-chrome__navigate(tabId, url: "https://studio.boardgamearena.com/studiogame?game={GAME_NAME}")

Then:

const links = Array.from(document.querySelectorAll('a'));
links.find(a => a.textContent.includes('Reload game informations'))?.click();
links.find(a => a.textContent.includes('Reload statistics'))?.click();
links.find(a => a.textContent.includes('Reload game options'))?.click();

---

Git Commits

Commit automatically after each completed step — do not wait for the user to ask. Each commit should capture a coherent, working (or at least lint-passing) state.

Commit points (at minimum):

• After scaffold download and project structure setup (1.1–1.3)
• After rules analysis and questions document (1.4)
• After each implemented game state or feature (e.g., "feat: implement draft phase", "feat: add scoring")
• After each successful bug fix cycle in Phase 3
• After any significant refactoring

git add -A && git commit -m "feat: description of what was done

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>"

Key rule: smaller, frequent commits are better than large ones. If a step involves multiple independent changes (e.g., implementing two unrelated game states), commit each separately.

---

BGA Studio Warnings (non-blocking)

After first deploy, BGA Studio may show these warnings — they are non-blocking for development:

Warning	Fix
"This game doesn't have a description"	Fill in the Game Metadata Manager on BGA Studio (UI, not code)
"This game doesn't have a valid BGG_ID"	Set 'bgg_id' => 0 in gameinfos.inc.php until a BGG page exists. Then reload game informations. When ready to publish, see references/bgg-submission.md.

---

Finding the correct GAME_ID for the lobby

The numeric GAME_ID is not the same as the game's internal ID visible in the page source (game_id). Get it from the "Play" link on the manage page:

// On the studiogame page, get the correct lobby URL:
Array.from(document.querySelectorAll('a')).find(a => a.href.match(/lobby\?game=\d+/))?.href
// → "https://studio.boardgamearena.com/lobby?game=XXXXX"  ← use this number

---

Common Initial Errors

Error	Fix
reflexion_time cannot be initialized	Move initGameStateLabels from constructor to initTable()
Constant X already defined	Migrate to public const on the Game class (see 2.1). For legacy code that must keep define(), guard each one: defined('X') || define('X', …)
Access level must be public	getAllDatas, getGameProgression must be public
Invalid id for state class	Delete scaffold state files from server via SFTP
Unknown statistic id	Reload statistics via BGA Studio manage panel
This transition (X) is impossible	Return state class from act method instead of calling setPlayerNonMultiactive(id, 'name')
too many authentication failures	Add -o IdentitiesOnly=yes to SSH/SCP commands
Scores not showing at game end	Write scores with $this->bga->playerScore->set($pid, $score) in state 98, not state 99
Unknown column 'X' in 'field list'	Check (a) inline -- comments in dbmodel.sql (see "No SQL Comments"); (b) the table was created from an older dbmodel.sql — BGA does not auto-migrate (see "BGA Schema Changes During Development"); (c) the name is reserved (see "Table Name Conflicts").
static::DbQuery or self::DbQuery	PHP 8.4 warns on static calls to instance methods, corrupting JSON. Always use $this->DbQuery(...). Same applies to all other DB helpers.
Logic bug: graph/query silently missing rows	getCollectionFromDb() uses the first selected column as the PHP array key — duplicate values silently overwrite each other. Always put a unique column (e.g., id, move_number) first: SELECT move_number, from_position, to_position FROM ... not SELECT from_position, to_position FROM ....

---

BGA Framework — Table Name Conflicts

Rule: prefix every custom table with a game-specific tag (e.g., mygame_moves, mygame_board). Never use these reserved names: moves, player, global, stats, gamelog, replaysavepoint, or anything starting with bga_. Collisions cause CREATE TABLE IF NOT EXISTS to silently no-op — see TECHNICAL_NOTES.md for the mechanism.

---

dbmodel.sql — No SQL Comments At All

Critical rule: write zero -- comments inside dbmodel.sql — anywhere in the file. Document the schema in a separate Markdown file (e.g., SCHEMA.md) instead. See TECHNICAL_NOTES.md for why (BGA collapses newlines before sending the file to MySQL, turning any -- into a comment that eats the rest of the file).

Safe pattern — self-documenting column names, no comments:

CREATE TABLE IF NOT EXISTS `mygame_moves` (
  `move_number`  INT(3)  NOT NULL,
  `player_id`    INT(10) NOT NULL,
  `from_position` INT(2)  NOT NULL,
  `to_position`   INT(2)  NOT NULL,
  PRIMARY KEY (`move_number`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

---

BGA Schema Changes During Development

dbmodel.sql runs once per new game table instance (when setupNewGame is called). CREATE TABLE IF NOT EXISTS will silently skip if a table already exists with a wrong schema.

When the schema is wrong on an existing table:

1. Quit all game table instances — manually in the browser, or programmatically from the game page (see 3.5b)
2. Create a fresh table — the correct dbmodel.sql will be applied
3. If the table name conflicts with a BGA internal table, rename it (e.g., moves → mygame_moves) and redeploy before creating the fresh table

---

Economy — Keeping Token Usage Low

• Use javascript_tool (DOM interaction) not computer (pixel coordinates)
• Use read_console_messages with a pattern filter, not read_page
• Reuse one browser tab for the whole session
• No screenshots unless explicitly requested

---

BGA Best Practices & Pitfalls (from docs + experience)

PHP / Server

• DB integers return as strings — always cast: (int)$row['value']
• Use bga_rand(min, max) for dice/random — rand() and mt_rand() forbidden in review
• Never use TRUNCATE or DROP — they do implicit commits that break BGA's transaction rollback
• Never call getCurrentPlayerId() in setupNewGame() or args methods — causes "Not logged" errors. (For zombieTurn(), see Zombie handling below.)
• Active player can only change in GAME-type states — activeNextPlayer() / changeActivePlayer() are no-ops inside ACTIVE_PLAYER states
• Args methods must return arrays — never int/string, never modify DB in args
• At least one notification per action is required (state transitions count)
• Notification size limit: 128KB total across bundled requests
• getObjectListFromDB($sql) returns a simple array — use it instead of getCollectionFromDb when the first selected column may have duplicates (see Common Initial Errors for the keying pitfall)
• String comparison: use === not == — hex colors like '4baae2' miscast with ==
• Action autowiring (new framework): #[PossibleAction] + typed parameters = no action.php needed
• Forbidden action parameter names: $args, $activePlayerId, $currentPlayerId — reserved by framework
• escapeStringForDB($str) — mandatory for any player-supplied string in SQL
• Use clienttranslate() for all notification messages — literal text only, no variables inside
• Wrap UserException messages in clienttranslate() — they're displayed to the player. SystemException / VisibleSystemException go to server logs and stay untranslated. See references/translations.md for the full i18n workflow (alpha vs beta, "Display dummy translation" debug button, raw-value-vs-translated-label pattern)
• PlayerStats::init has no $playerId — signature is init($name, $value, bool $updateTableStat = false). Passing a player ID silently casts to true and crashes setupNewGame. Inits all players in one call — no loop. (inc/set DO take $playerId.)

JavaScript / Client

• setup() runs before onEnteringState() — render complete initial state in setup using gamedatas.gamestate.args
• Call setupPromiseNotifications() in setup() — auto-detects all notif_* methods
• In MULTIPLE_ACTIVE_PLAYER states: active players are NOT active yet in onEnteringState — use onUpdateActionButtons for active-dependent UI
• performAction only from user events — NEVER from notifications, loops, callbacks, or state methods
• slideToObject() returns dojo animation — must call .play() on the result
• Slide methods incompatible with CSS transforms (scale, zoom, rotate)
• Check bgaAnimationsActive() before animating
• parseInt(value, 10) — notification args are strings, += will concatenate instead of add
• Hotseat shares gamedatas across players — no per-player client data
• Read-only detection: check isCurrentPlayerSpectator() || typeof g_replayFrom != 'undefined' || g_archive_mode
• Prefix CSS classes with game name — e.g., mygame_selected, not selected
• attachToNewParent clones the element — destroys original references and dojo.connect handlers
• Never call setState in notifications — causes race conditions and breaks replays

Zombie handling

• Never call getCurrentPlayerId() in zombieTurn() — use the $active_player_id parameter
• States must have a "zombiePass" transition (exact spelling)
• Cannot end game from zombie method — must continue game logic

Debug tips

• Express stop on the table config page kills a stuck game (overrides confirm with window.confirm = () => true)
• Temporary debug actions (#[PossibleAction]) are effective for testing end-game / specific positions — call via gameui.ajaxcall, remove before commit
• Full SQL/request logs: /1/GAME_NAME/GAME_NAME/logaccess.html?table=N
• CSS state class: #overall-content gets .gamestate_playerTurn etc. — use for conditional visibility without JS