🔢 15 Puzzle

📖 Overview

The 15 Puzzle is a classic sliding tile puzzle invented in the 1870s. It consists of numbered tiles (1-15) arranged in a square grid with one empty space. Your goal is to arrange the tiles in numerical order by sliding them into the empty space.

This timeless puzzle challenges your spatial reasoning and strategic planning skills. Every move counts toward your final score!

📋 Rules

• Click any tile adjacent to the empty space to slide it
• Only tiles directly next to the empty space can move
• Arrange all tiles in numerical order (left to right, top to bottom)
• The empty space should end up in the bottom-right corner
• Try to solve the puzzle in the fewest moves possible

🎮 Controls

• Mouse: Click any tile adjacent to the empty space
• Arrow Keys: Move tiles in the direction of the arrow
• Difficulty Selector: Choose grid size (3×3, 4×4, or 5×5)
• New Game: Generate a fresh puzzle
• Shuffle: Randomize the current puzzle
• Sound Toggle: Enable/disable sound effects

🏆 Scoring

Your score is determined by two factors:

• Move Count: Fewer moves = better score
• Time: Tracked for personal records
• Best Score: Your lowest move count is saved locally

Beginners typically solve in 150-200 moves. Experienced players aim for under 100 moves, while experts can complete it in under 60 moves!

💡 Tips

• Start by positioning the top row (1-4) correctly
• Work row by row from top to bottom
• For the last two rows, use rotation patterns
• Don't rush - think several moves ahead
• Practice with easier difficulties first (3×3)
• The puzzle is always solvable - never give up!

❓ FAQ

Q: Are all puzzles solvable?
A: Yes! This game uses the inversion count algorithm to ensure every generated puzzle has a valid solution.

Q: What's the optimal solution?
A: While the puzzle is always solvable, finding the absolute shortest path is computationally complex. Focus on improving your move count with practice!

Q: Can I use keyboard controls?
A: Yes! Use arrow keys to move tiles in the direction of the empty space.