Evil Sudoku — Play Hardcore Extreme Master Puzzles Online & Printable
Tackle authentic Evil Sudoku puzzles featuring only 22-24 initial clues. Designed for advanced solvers who want to master X-Wings, Swordfish, XY-Wings, and candidate coloring without trial-and-error. 100% logic-deducible with unique solutions.
Evil Sudoku Strategy & FAQ
What makes a Sudoku puzzle 'Evil' or Extreme?
Evil Sudoku features only 22-24 initial clues. Basic elimination techniques (naked singles) are insufficient; solvers must employ advanced strategies like X-Wing, Swordfish, XY-Wing, and coloring chains.
Does Evil Sudoku require guessing or trial-and-error?
No! True Evil Sudoku puzzles generated on Sudoku Daily never require guessing. Every single digit can be determined strictly through pure mathematical logic.
How can I practice candidate pencil marks?
You can toggle the online pencil marks mode to jot down small candidate numbers in each empty cell, or print our spacious A4 challenge sheet to solve by hand with pencil and eraser.
Is there a daily Evil Sudoku challenge?
Yes, every day a brand-new, uniquely seeded Evil/Extreme puzzle is released with complete solutions.