Entropy TicTacToe

A multiplayer strategy game that combines traditional TicTacToe with hidden information and probability mechanics.

How It Works

The game uses a 3x3 board with 9 hidden pieces. Each board contains exactly 5 pieces of one symbol (X or O) and 4 of the other, but players don't know which symbol has the majority. Every piece shows probability percentages that update as the game progresses.

Placement Phase: Players alternate placing pieces on empty cells. All symbols remain hidden.

Reveal Phase: Players take turns revealing pieces to find their symbols and form three in a row.

The key challenge is using probability information and deduction to make strategic decisions about where to place and reveal pieces.

Setup Instructions

Game Rules

• 3x3 grid with 9 total pieces
• Exactly 5 of one symbol, 4 of the other
• Players don't know which symbol they need
• Each piece displays probability percentages (randomly assigned which number represents X or O)
• Probabilities update after each reveal following Monty Hall theorem to determine the new percentages
• Win by getting 3 symbols in a row, column, or diagonal
• Two phases: placement then reveal

Technical Details

• Frontend: React with TypeScript
• Backend: FastAPI with WebSocket communication
• Real-time multiplayer with room-based matchmaking
• Server-authoritative game logic

Setup

Requirements

• Python 3.8 or higher
• Node.js 16 or higher
• npm package manager

Backend Setup

1. Navigate to backend directory:

   cd backend

2. Create virtual environment:

   python -m venv venv
   venv\Scripts\activate    # Windows
   source venv/bin/activate # macOS/Linux

3. Install dependencies:

   pip install -r requirements.txt

4. Run server:

   python main.py

   Server runs on http://localhost:8000

Frontend Setup

1. Navigate to frontend directory:

   cd frontend

2. Install dependencies:

   npm install

3. Start development server:

   npm start

   Frontend runs on http://localhost:3000

Playing the Game

1. Open http://localhost:3000 in two browser windows
2. One player creates a room and shares the room code
3. Second player joins using the room code
4. Game starts automatically when both players are ready

Development

The backend uses in-memory storage, so rooms reset when the server restarts. For production use, consider adding persistent storage.

WebSocket endpoints:

• GET /create_room - Create new room
• WebSocket /ws/{room_code} - Game communication

Game state is managed server-side to prevent cheating.