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Comparison

Sudoku vs Killer Sudoku

Same 9×9 skeleton — Killer adds dashed cages and sums.

Play classic Sudoku → What is Sudoku?

Classic Sudoku uses only row, column and box uniqueness. Killer Sudoku keeps those rules and adds cages: the digits inside a dashed region must sum to a small clue and usually cannot repeat inside the cage.

That single addition changes the feel completely. You will use combination knowledge (which sets of digits sum to 10 in three cells, and so on) alongside classic techniques. Many players find Killer harder at the same “newspaper star” rating.

Learn classic Easy → Medium first. Then read Killer rules and try a gentle Killer once singles and pairs are automatic.

Side-by-side

Aspect Sudoku Killer Sudoku
Extra marks None Cages + sum clues
Arithmetic None Cage sums (45-rule helps)
Technique base Singles, pairs, fish… Classic + combos + cage logic
Best first step Easy 9×9 or mini After Medium classic fluency

Pick Sudoku if…

  • ·Brand new to number puzzles
  • ·You want zero arithmetic
  • ·You are teaching kids first

Pick Killer Sudoku if…

  • ·Classic Medium is too easy
  • ·You like sum combinations
  • ·You want a harder daily challenge

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FAQ

Should I learn Sudoku before Killer?
Yes. Killer assumes you already see singles and pairs quickly. Without that, cage sums become overwhelming.
Where are Killer rules on Zeloku?
See the Killer Sudoku rules page for cages, the 45 rule and beginner tips. Classic play remains on Play Sudoku and Daily hubs.

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