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Sudoku X

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Sudoku X Game Guide

📖 About

Sudoku X adds an exciting twist to the classic puzzle! In addition to rows, columns, and 3×3 boxes, both main diagonals must also contain digits 1-9 exactly once. This extra constraint creates new solving opportunities and requires adjusted strategies. Perfect for Sudoku masters seeking new challenges!

🎯 Objectives

Fill the grid so that each row, column, 3×3 box, AND both diagonals contain digits 1-9 exactly once.

🎮 How to Play

Click a cell and enter 1-9. Each row, column, 3x3 box, and both diagonals must contain all digits 1-9 exactly once. Blue cells highlight diagonal constraints.

⌨️ Controls

Click a cell and press 1-9 to enter a number. Press Delete or 0 to clear. Arrow keys navigate between cells.

⚙️ Game Mechanics

  • ▸ Each row must contain digits 1-9 exactly once
  • ▸ Each column must contain digits 1-9 exactly once
  • ▸ Each 3×3 box must contain digits 1-9 exactly once
  • ▸ Both diagonals must contain digits 1-9 exactly once
  • ▸ Diagonal cells have additional constraints

✨ Features

  • ★ Multiple difficulty levels
  • ★ Highlight diagonal cells
  • ★ Auto-check for errors
  • ★ Pencil marks for candidates

💡 Tips

  • ✓ Use diagonals as additional constraints
  • ✓ Diagonal cells have fewer possible values
  • ✓ Start with diagonal intersections
  • ✓ Classic Sudoku strategies still apply

❓ Frequently Asked Questions

What makes Sudoku X different from regular Sudoku?
The main diagonals (from top-left to bottom-right AND from top-right to bottom-left) must also contain digits 1-9 exactly once. This adds 18 extra cells with diagonal constraints!
Should I focus on diagonals first?
Diagonal cells are powerful because they participate in both row, column, AND diagonal constraints. Starting with diagonal intersections can eliminate candidates quickly.
Can I use regular Sudoku techniques?
Absolutely! Naked pairs, hidden singles, X-wings, and all classic techniques work. The diagonal constraint just gives you more information to work with.
Is Sudoku X harder than regular Sudoku?
Generally yes, because you have more constraints to satisfy. However, these extra constraints can also make certain deductions easier once you learn to use them.

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