Saturday, March 21

Killer Sudoku

Expert schedule 0:00

Arrow keys to navigate · 1–9 to fill · Del to erase · N for notes

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How to Play Killer Sudoku

lightbulb The Basics

Killer Sudoku combines classic Sudoku with arithmetic. The grid is divided into cages — groups of cells outlined with dashed borders. Each cage shows a target sum in its top-left corner.

Fill every cell with digits 1-9 following standard Sudoku rules (no repeats in any row, column, or 3×3 box). Additionally, the digits in each cage must add up to the cage's target sum, and no digit can repeat within a cage.

touch_app How to Solve

Click a cell then use the number pad or keyboard (1-9) to enter a digit. Press 0 or Backspace to clear.

Notes mode: Toggle the Notes button to pencil in candidate numbers. Notes appear as small digits in the corner of the cell.

Cage sums: The small number in the top-left of each dashed region is the target sum. All digits in that cage must add up to exactly that number.

tips_and_updates Tips & Strategies

1.Learn key combinations. A 2-cell cage summing to 3 can only be 1+2. A 2-cell cage summing to 17 can only be 8+9. These "forced" cages are your best starting points.
2.Use the 45 rule. Each row, column, and 3×3 box sums to 45. If you know most cage sums in a region, you can calculate the missing digit(s).
3.No repeats in cages. A 3-cell cage summing to 6 must be 1+2+3 (the only way without repeats). This is a powerful constraint.
4.Cross-reference. Use standard Sudoku elimination alongside cage constraints. If a digit is ruled out by row/column, it's also ruled out in the cage.

emoji_events Tracking Your Progress

Each daily Killer Sudoku is timed. Your completion time is recorded on your profile. Solve one every day to build your streak and unlock achievements. Use the Archive to revisit previous puzzles.

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