How to play Sudoku X: rules, tips and strategies

Sudoku X is a harder version of the classic Sudoku that not only trains the brain, but also challenges even experienced puzzle enthusiasts. In this article you will learn what Sudoku X is, how to solve it correctly. We'll go over the basic rules, effective strategies, and frequently asked questions so you can easily master this game even if you've never heard of it before.

What is Sudoku X?

Sudoku X is a variation of classic Sudoku, but with one important difference: in addition to rows, columns, and 3×3 squares, it also takes into account two diagonals. This means that each diagonal must also include all digits from 1 to 9 without repeats.

Differences from regular Sudoku:

This increase in complexity makes the game more interesting and requires a different approach to solution strategy.

Rules of Sudoku X

It's not hard to play Sudoku X if you understand its basic rules. Here's what's important to know:

Basic rules:

• The field consists of 9 rows, 9 columns and 9 3×3 blocks.
• Numbers 1 through 9 must fill each row, column and block without repetition.
• The main and side diagonals (corner to corner) must also contain no repeating numbers.

Strategies and tips for solving Sudoku X

Solving Sudoku X requires care and patience. Here are some techniques that will help:

• Start simple
  Look for rows, columns, blocks, or diagonals that already have a lot of numbers in them. These are the easiest to fill in.
• Use the elimination method
  Eliminate numbers that cannot stand in certain positions. This way you will find the correct option faster.
• Marks and candidates
  Use a pencil or virtual notes to write in possible numbers. This is especially useful for complex levels.
• Watch the diagonals
  Check each new number not only along the row and column, but also along the diagonal. This will help avoid frequent mistakes.
• X-Wing technique (for advanced)
  If you are facing a difficult level, learn the X-Wing technique - it allows you to eliminate candidates by analyzing cross positions.
• Pointing Pairs in X Sudoku: a strategy using diagonals.
  
  

  

  In X Sudoku, diagonals play a special role and open up new tactical possibilities. Because the cells on the diagonals do not overlap in rows and columns, they create unique situations that can be used in the solution.
  
  For example, if two cells on the diagonal contain the same candidate, they form a kind of "pointing pair". These cells are on opposite corners of an imaginary rectangle. This means that opposite cells in this rectangle cannot contain the same candidate - a powerful way to eliminate digits and speed up the process.
  
  Consider a situation: cells D6 and J1 both contain candidate 1. Since either D6 or J1 will necessarily be a 1, cells D1 and J6, which “see” both of these points, cannot contain a 1. This allows you to safely remove 1 from these positions.


• Unique rectangles in X sudoku: what to look out for
  
  
  Many advanced players use the unique rectangle technique to eliminate candidates and avoid mistakes when solving classic puzzles. But in X Sudoku (or Sudoku X), this strategy requires extra caution.
  
  All standard types of unique rectangles do apply to Sudoku X, but there is an important nuance: if at least one of the four cells of such a rectangle is on a diagonal, it becomes risky to use this technique.
  
  Why? In classical Sudoku, if you notice a so-called “death pattern” (when two pairs of candidates are free to swap places), this is a signal that you can eliminate one of the candidates to avoid ambiguity. But in X sudoku, where additional diagonal constraints apply, this approach no longer works.
  
  If at least one corner of a rectangle lies on a diagonal, swapping pairs may violate the uniqueness rule on the diagonal, leading to an error. Therefore, you can use the logic of unique rectangles only when all four cells are off-diagonals.

Conclusion

Sudoku X is a great logic puzzle game for those who want to challenge themselves and develop analytical thinking. Follow the rules, use proven strategies and practice every day. With each new level you will feel your skill growing!

Ready to get started? Try playing Sudoku X online right now - and discover a new level of fun with logic games.