HTML Chess Game - Phase 1 MVP Complete ♟️

A complete, fully-functional chess game implementation using vanilla HTML, CSS, and JavaScript with all FIDE rules.

🎯 Current Status: Phase 1 MVP Core - COMPLETE ✅

Implemented Features

• ✅ Complete 8x8 chess board with coordinate system
• ✅ All 6 piece types (Pawn, Knight, Bishop, Rook, Queen, King)
• ✅ Full move validation engine
• ✅ Check, Checkmate, and Stalemate detection
• ✅ Special moves: Castling, En Passant, Pawn Promotion
• ✅ Drag-and-drop interface (desktop)
• ✅ Click-to-move interface (desktop + mobile)
• ✅ Touch support for mobile devices
• ✅ Move history with PGN notation
• ✅ Captured pieces display
• ✅ Undo/Redo functionality
• ✅ Game state persistence (localStorage)
• ✅ Responsive design
• ✅ All FIDE chess rules implemented

🚀 Quick Start

Installation

# Navigate to chess-game directory
cd chess-game

# Install dependencies
npm install

Development

# Start development server (Vite)
npm run dev

# Open browser to http://localhost:5173

Testing

# Run unit tests
npm test

# Run tests in watch mode
npm run test:watch

# Run tests with coverage
npm run test:coverage

# Run end-to-end tests
npm run test:e2e

Build for Production

# Create production build
npm run build

# Preview production build
npm run preview

📁 Project Structure

chess-game/
├── css/
│   ├── board.css          # Chess board styling
│   ├── pieces.css         # Chess piece styling
│   ├── game-controls.css  # UI controls styling
│   └── main.css           # Global styles
│
├── js/
│   ├── game/
│   │   ├── Board.js       # Board state management
│   │   └── GameState.js   # Game state & history
│   │
│   ├── pieces/
│   │   ├── Piece.js       # Base piece class
│   │   ├── Pawn.js        # Pawn with En Passant & Promotion
│   │   ├── Knight.js      # Knight (L-shaped movement)
│   │   ├── Bishop.js      # Bishop (diagonal)
│   │   ├── Rook.js        # Rook (horizontal/vertical)
│   │   ├── Queen.js       # Queen (rook + bishop)
│   │   └── King.js        # King with Castling
│   │
│   ├── engine/
│   │   ├── MoveValidator.js  # Move validation & check detection
│   │   └── SpecialMoves.js   # Castling, En Passant, Promotion
│   │
│   ├── controllers/
│   │   ├── GameController.js  # Main game controller
│   │   └── DragDropHandler.js # User input handling
│   │
│   ├── views/
│   │   └── BoardRenderer.js   # Board rendering (CSS Grid)
│   │
│   └── main.js            # Application entry point
│
├── tests/
│   ├── unit/              # Unit tests
│   └── integration/       # Integration tests
│
├── index.html             # Main HTML file
├── package.json           # Dependencies & scripts
└── README.md              # This file

🎮 How to Play

1. Start a Game: Click "New Game" to begin
2. Make Moves:
   • Drag & Drop: Click and drag pieces to move them
   • Click-to-Move: Click a piece, then click destination square
   • Touch: Tap piece, then tap destination (mobile)
3. View History: See all moves in algebraic notation
4. Undo/Redo: Navigate through move history
5. Special Moves:
   • Castling: Move king two squares toward rook
   • En Passant: Automatic when conditions met
   • Promotion: Choose piece when pawn reaches end rank

🏗️ Architecture

Design Patterns

• Model-View-Controller (MVC): Clean separation of concerns
• Object-Oriented: Inheritance-based piece system
• Event-Driven: Comprehensive game event system
• Module Pattern: ES6 modules for organization

Key Components

1. Board System

import { Board } from './js/game/Board.js';

const board = new Board();
board.setupInitialPosition();
const piece = board.getPiece(6, 4); // Get piece at e2

2. Piece Movement

import { Knight } from './js/pieces/Knight.js';

const knight = new Knight('white', { row: 7, col: 1 });
const validMoves = knight.getValidMoves(board);

3. Move Validation

import { MoveValidator } from './js/engine/MoveValidator.js';

const isLegal = MoveValidator.isMoveLegal(board, piece, toRow, toCol, gameState);
const isCheckmate = MoveValidator.isCheckmate(board, 'white', gameState);

4. Game Controller

import { GameController } from './js/controllers/GameController.js';

const game = new GameController();
const result = game.makeMove(6, 4, 4, 4); // e2 to e4

if (result.success) {
    console.log('Move:', result.move.notation);
    console.log('Status:', result.gameStatus);
}

📋 API Reference

See /docs/API_REFERENCE.md for complete API documentation.

Quick Examples

Initialize Game

const game = new GameController({
    autoSave: true,
    enableTimer: false
});

game.on('move', (data) => {
    console.log('Move made:', data.move.notation);
});

game.on('checkmate', (data) => {
    console.log('Winner:', data.winner);
});

Make a Move

const result = game.makeMove(fromRow, fromCol, toRow, toCol);

if (!result.success) {
    console.error('Invalid move:', result.error);
}

Get Legal Moves

const piece = game.board.getPiece(row, col);
const legalMoves = game.getLegalMoves(piece);

// Returns: [{row: 4, col: 4}, {row: 5, col: 4}, ...]

✅ FIDE Rules Compliance

All rules comply with official FIDE Laws of Chess:

• ✅ Article 3.1-3.6: Piece movement (all 6 pieces)
• ✅ Article 3.8: Special moves (castling, en passant, promotion)
• ✅ Article 5: Game completion (checkmate, stalemate, draws)
• ✅ Article 9: Draw conditions (50-move rule, repetition, insufficient material)

🧪 Testing

Test Coverage Goals

• Unit Tests: 80%+ code coverage
• Integration Tests: Complete game scenarios
• E2E Tests: UI interactions and workflows

Running Tests

# All tests
npm test

# Watch mode (auto-rerun on changes)
npm run test:watch

# Coverage report
npm run test:coverage

# Playwright E2E tests
npm run test:e2e

Example Test

import { Board } from './js/game/Board.js';

describe('Board', () => {
    it('should initialize 8x8 grid', () => {
        const board = new Board();
        expect(board.grid.length).toBe(8);
        expect(board.grid[0].length).toBe(8);
    });
});

📊 Code Quality

Standards

• ES6+ modules and modern JavaScript
• JSDoc comments on all public methods
• Consistent naming conventions
• Modular architecture (each file < 500 lines)
• No hardcoded secrets or configuration

Linting & Formatting

# Lint code
npm run lint

# Auto-fix linting issues
npm run lint:fix

# Format code with Prettier
npm run format

🌐 Browser Support

• Chrome 60+
• Firefox 54+
• Safari 10.1+
• Edge 79+

Requirements:

• ES6+ support
• CSS Grid
• Drag and Drop API
• LocalStorage API
• Touch Events (mobile)

📱 Responsive Design

• Desktop: Full drag-and-drop experience
• Tablet: Touch-optimized controls
• Mobile: Simplified UI, touch-friendly

Breakpoints:

• Desktop: > 968px
• Tablet: 640px - 968px
• Mobile: < 640px

🔧 Configuration

package.json Scripts

{
  "dev": "vite",                      // Development server
  "build": "vite build",              // Production build
  "preview": "vite preview",          // Preview production
  "test": "jest",                     // Run tests
  "test:watch": "jest --watch",       // Watch mode
  "test:coverage": "jest --coverage", // Coverage report
  "test:e2e": "playwright test",      // E2E tests
  "lint": "eslint js/**/*.js",        // Lint code
  "lint:fix": "eslint --fix",         // Auto-fix
  "format": "prettier --write"        // Format code
}

🚧 Roadmap

Phase 2: AI & Analysis

• AI opponent (Minimax algorithm)
• Move suggestions
• Position evaluation
• Opening book database

Phase 3: Polish & Features

• Sound effects
• Smooth animations
• Multiple themes
• User preferences
• Accessibility improvements
• Network multiplayer

Phase 4: Advanced

• Chess puzzles
• Game analysis
• Move timer/clock
• PGN import/export
• Tournament mode

📚 Documentation

• /docs/API_REFERENCE.md - Complete API documentation
• /docs/IMPLEMENTATION_GUIDE.md - Implementation details
• /docs/CHESS_RULES.md - Chess rules reference
• /docs/DEVELOPER_GUIDE.md - Development guide
• /docs/implementation/PHASE1_COMPLETION_REPORT.md - Phase 1 report

🤝 Contributing

This is a learning project implementing FIDE chess rules. For issues or suggestions:

1. Review existing documentation
2. Check implementation guide
3. Verify against FIDE rules
4. Submit detailed issue/PR

📝 License

MIT License - Feel free to use and modify

🏆 Achievements

• ✅ Phase 1 Complete: Full chess game with all FIDE rules
• ✅ 4,500+ Lines: Clean, documented code
• ✅ 15 Modules: Well-organized architecture
• ✅ 100% Features: All planned Phase 1 features
• ✅ FIDE Compliant: Official chess rules
• ✅ Mobile Ready: Touch-optimized interface

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🎯 Quick Reference

Start Playing

npm install
npm run dev
# Open http://localhost:5173

Key Files

• Entry Point: /js/main.js
• Game Logic: /js/controllers/GameController.js
• Board: /js/game/Board.js
• Validation: /js/engine/MoveValidator.js

Important Classes

• GameController - Main game orchestrator
• Board - Board state management
• MoveValidator - Move validation engine
• BoardRenderer - Visual rendering
• DragDropHandler - User input

Game Events

• move - Move executed
• check - King in check
• checkmate - Game won
• stalemate - Draw
• promotion - Pawn promotion available

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Status: Phase 1 MVP Core ✅ Complete Ready For: Testing, Phase 2 Development Last Updated: November 22, 2025