Hardest Sudoku

Monster puzzle

Easter Monster

11.0SE grade

By The Hardest Sudoku Team · Last updated

The puzzle as published (21 clues). Solution not shown.

SE grade
11.0
Creator
JPF (forum.enjoysudoku.com)
Year
2007

Origin and lore

Easter Monster is one of the most famous symmetric monsters, posted around Easter 2007. Its striking diagonal clue pattern made it a touchstone puzzle and spurred research into specialized techniques (Naked/Hidden Double Loops, the 'SK Loop') that exploit its structure. It remains a classic example of high-SE-grade difficulty.

Source: SudokuSnake.com (Easter Monster); forum.enjoysudoku.com (Easter Monster thread).

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