Medium Palindrome Sudoku
Ready to sharpen your skills? Medium Palindrome Sudoku puzzles introduce interactions between the variant constraint and classic Sudoku techniques. You'll need to combine both skill sets to progress.
What to expect at Medium level
Medium Palindrome Sudoku puzzles require you to combine the variant constraint with standard Sudoku deduction - Naked pairs, hidden singles, and unit scans. The constraint is more tightly woven into the grid, so you'll need to think a few steps ahead.
Best suited for players comfortable with Easy Palindrome Sudoku who want to build their pattern recognition.
Difficulty overview
About Palindrome Sudoku
Palindrome Sudoku marks lines on the grid whose digit sequence must be a palindrome — reading the same in both directions. If a line has cells A-B-C-D-E, then A=E and B=D, while C is the central digit. This creates pairs of cells that must share the same value, acting as powerful equality constraints across the grid.
Solving Techniques for Medium Level
| Technique | Description | Level |
|---|---|---|
| Mirror Pair Identification | In a palindrome of length L, cell i and cell L+1−i must share the same digit. Identify all mirror pairs before solving. | Beginner |
| Centre Cell Freedom | The central cell of an odd-length palindrome has no mirror constraint — it is only restricted by standard row/column/box rules. | Beginner |
| Mirror Propagation | Once one cell of a mirror pair is determined, immediately set its partner to the same value. | Intermediate |
Master these, then take on Hard Killer Sudoku to learn Advanced techniques.