Strategies

What is Killer Sudoku? Killer Sudoku (also known as “Sum Sudoku” or “Sumdoku”) combines elements of sudoku and kakuro, creating a more challenging and strategic puzzle experience. If you’ve mastered traditional sudoku and are looking for your next challenge, Killer Sudoku is the perfect next step. How Killer Sudoku Differs from Classic Sudoku The Basic Rules Killer Sudoku follows all the standard sudoku rules: 9×9 grid divided into nine 3×3 boxes Each row, column, and box must contain digits 1-9 No digit can repeat in any row, column, or box The Killer Twist What makes Killer Sudoku unique: ...

Beyond Basic Sudoku: Advanced Techniques Once you’ve mastered the fundamentals of sudoku, you may find yourself stuck on harder puzzles where basic scanning and elimination aren’t enough. This guide introduces 10 advanced techniques that expert solvers use to crack even the most challenging puzzles. Before You Begin: Prerequisites These advanced techniques assume you’re comfortable with: Pencil marks (candidates): Marking possible numbers in each cell Naked singles: Cells with only one possible candidate Hidden singles: Numbers that can only go in one place in a row/column/box Naked pairs/triples: Sets of cells that must contain specific numbers If you’re not familiar with these basics, start with our Beginner’s Guide first. ...