♟️ CLI Chess Engine (Minimax AI)

This project is a Command Line Interface (CLI) based Chess Engine built in Python. It allows a user to play chess directly in the terminal against an AI powered by the Minimax algorithm with Alpha-Beta pruning.

The application is fully terminal-based and does not require any graphical interface.

---

🚀 Features

• Play chess in the terminal
• AI opponent using Minimax algorithm
• Alpha-Beta pruning for efficiency
• Quiescence search for better move evaluation
• Colored chess board with Unicode pieces
• Adjustable difficulty levels
• Undo and restart functionality

---

🧰 Prerequisites

Make sure you have the following installed on your system:

• Python 3.10 or higher
• pip (Python package manager)

To check Python version:

python --version

---

⚙️ Installation & Setup

Follow these steps carefully to set up the project.

1. Clone the Repository

git clone https://github.com/your-username/cli-chess-engine.git
cd cli-chess-engine

---

2. Create a Virtual Environment (Recommended)

For Windows:

python -m venv venv
venv\Scripts\activate

For macOS/Linux:

python3 -m venv venv
source venv/bin/activate

---

3. Install Dependencies

pip install python-chess

---

▶️ Running the Application

Run the following command in your terminal:

python chess_engine.py

---

🎮 How to Play

• The chessboard will appear in the terminal
• You play as White, and the AI plays as Black
• Enter moves using Standard Algebraic Notation (SAN)

Examples:

• e4 → Move pawn
• Nf3 → Move knight
• O-O → Castle kingside
• exd5 → Capture move

---

🕹️ Commands

Command	Description
e4, Nf3	Make a move
undo	Undo last move
restart	Restart the game
help	Show command list
exit	Quit the game

---

🎯 Difficulty Levels

At the start of the game, you will be prompted to choose a difficulty level:

• 1 → Easy (fast, shallow search)
• 2-3 → Medium (balanced)
• 4+ → Hard (slower but stronger AI)

---

🧠 How the AI Works

The chess engine uses the following techniques:

• Minimax Algorithm: Simulates future moves assuming optimal play
• Alpha-Beta Pruning: Skips unnecessary branches to improve speed
• Quiescence Search: Handles tactical positions beyond depth limit
• Evaluation Function: Scores positions based on material balance

---

📁 Project Structure

.
├── chess_engine.py   # Main CLI application and engine logic
└── README.md         # Project documentation

---

⚠️ Notes

• Ensure your terminal supports ANSI colors for best experience

• Works best in:

  • Windows Terminal / PowerShell
  • VS Code Terminal
  • Linux / macOS terminals

---

📜 License

This project is open-source and available under the MIT License.

---

👨‍💻 Author

Divyansh Agarwal CSE Core, VIT Bhopal University (2025–2029)

---

This project demonstrates implementation of game theory and AI algorithms in a fully functional CLI-based application.