CageDokuKiller Sudoku vs Classic Sudoku: What Is Different?
By Andrew Boyko, developer of CageDoku · Updated
Both are Sudoku: every row, column and box contains 1 to 9 once. The difference is what the puzzle gives you.
Givens versus cages
Classic Sudoku starts with 20 to 30 given digits. Killer Sudoku starts with none (or very few) and instead divides the grid into cages whose digits add up to a printed sum. Digits cannot repeat inside a cage.
Techniques they share
Naked and hidden singles, pairs, triples, locked candidates and fish work in both. In Killer, cages often create these patterns for you.
Techniques only Killer has
- Cage combination tables (which digit sets can make a sum).
- The 45 rule, innies and outies.
- Min/max bounds and complements for large cages.
Who should switch?
If you like arithmetic and want to feel every cell connected to its neighbours, Killer is satisfying. If you prefer pure pattern scanning, classic or Diagonal will feel closer to home.
Which is harder?
It depends on the level. See Is Killer Sudoku harder than Sudoku? for an honest answer.
Frequently asked questions
Can I solve Killer Sudoku with classic techniques only?
Mostly yes after the first few placements, but the opening moves require cage combinations or the 45 rule.
Practice it in CageDoku
Free, ad-free Killer Sudoku and seven more variants. Hints name the technique and highlight the cells, so you learn why a digit goes where it goes.