KILLER SUDOKU GUIDE

Killer Sudoku Rules and Strategies

Killer Sudoku keeps the classic 9×9 Sudoku rule set, then adds cage sums that reward clean logic and careful arithmetic.

What is Killer Sudoku?

Killer Sudoku is a logic puzzle where every row, column, and 3×3 box still uses digits 1–9 once, while dotted cages must add up to their clue totals.

Core rules

  • Fill the 9×9 grid so each row, column, and 3×3 box contains 1–9 exactly once.
  • Every cage must add up to the small number shown in its corner.
  • Digits cannot repeat inside a cage, even when the cage crosses boxes or rows.

Beginner strategy

  • Start with cages that have very small or very large sums because their digit combinations are limited.
  • Use classic Sudoku scanning after each cage deduction to reveal singles in rows, columns, and boxes.
  • Write candidate sums lightly, then remove combinations as nearby rows and boxes become constrained.

Practice the logic

Sudoku Hot does not yet ship a dedicated cage-sum board, but you can build the same patience and scanning skill with hard, expert, and Hell Mode classic puzzles.

Play Hell Mode Sudoku

Killer Sudoku FAQ

What is the difference between Sudoku and Killer Sudoku?

Classic Sudoku uses row, column, and 3×3 box rules. Killer Sudoku keeps those rules and adds cage totals, so arithmetic becomes part of the logic.

Can digits repeat inside a Killer Sudoku cage?

No. A cage cannot contain repeated digits, even if the cells are in different rows, columns, or boxes.

Do I need to guess in Killer Sudoku?

A well-made Killer Sudoku puzzle can be solved with logic. Use cage combinations, classic Sudoku eliminations, and singles before guessing.