Python Chess Game

A complete chess game implementation in Python with GUI and AI player.

Features

• Complete chess rule implementation with all legal moves
• Special moves: castling, en passant, pawn promotion
• Chess AI with minimax algorithm and alpha-beta pruning
• Position evaluation based on material and strategic factors
• Network multiplayer over local network (LAN)
• Local multiplayer on the same computer
• Game state detection (checkmate, stalemate, draw conditions)
• Simple and clean GUI using Pygame

Requirements

• Python 3.6+
• Pygame 2.5.2+

Installation

1. Clone this repository or download the source code.
2. Install the required dependencies:

pip install -r requirements.txt

How to Play

Run the game with:

python main.py

Game Modes

The game offers three playing modes:

1. Singleplayer - Play against the AI with three difficulty levels
2. Local Multiplayer - Play against a friend on the same computer
3. Network Multiplayer - Play against a friend over a local network

Network Multiplayer

To play over a local network:

Option 1: Host a game

1. Select "Network Multiplayer" from the main menu
2. Click "Host Game"
3. Your computer will start both a server and act as a client
4. Tell your friend your IP address to connect to

Option 2: Join a game

1. Select "Network Multiplayer" from the main menu
2. Click "Join Game"
3. Enter the IP address of the host computer
4. Click "Connect"

Option 3: Dedicated server mode

You can also run a dedicated server (without GUI) on a computer:

python main.py --server

This will display the server's IP address which players can connect to.

Game Controls

• Click on a piece to select it
• Click on a highlighted square to move the selected piece
• The game automatically checks for valid moves, check, checkmate, and stalemate
• White plays first, followed by the AI (black)

Project Structure

• main.py - Main entry point
• fixed_menu.py - Menu system with multiple game modes
• chess_game/ - Main package containing game logic
  • game.py - Game loop and UI management
  • board.py - Chess board representation and game rules
  • pieces.py - Individual chess piece classes and movement rules
  • player.py - Player base class
  • ai.py - AI implementation with minimax and position evaluation
  • constants.py - Game constants and evaluation tables
  • network.py - Network multiplayer implementation
  • network_game.py - Network game management
• assets/ - Directory for piece images

Chess AI

The AI uses a minimax algorithm with alpha-beta pruning to search for the best move. It evaluates positions based on:

1. Material count - Basic piece values
2. Piece position - Positional tables for each piece type
3. King safety - Evaluation of king's safety including castling and pawn shield
4. Pawn structure - Evaluation of pawn formations including doubled pawns, isolated pawns, and passed pawns
5. Mobility - Count of available legal moves

Adding Custom Chess Pieces

The game looks for chess piece images in the assets directory. If you want to add your own piece images:

1. Create PNG images for each piece with these filenames:
   • White pieces: wP.png, wR.png, wN.png, wB.png, wQ.png, wK.png
   • Black pieces: bP.png, bR.png, bN.png, bB.png, bQ.png, bK.png
2. Place them in the assets/ directory

If no images are found, the game will use text-based pieces as a fallback.

License

This project is available under the MIT License.