Hell · Easy
The gentlest hell
About 28 givens plus cage sums — still tougher than classic medium.
Enter hellHell Mode
Hell Mode
Killer Sudoku at its most extreme: dotted cages with sum clues and far fewer givens than classic. Master tier starts with an empty grid — only cages.
Killer rules apply: every cage must hit its sum with no repeated digits — and mistakes still count.
Hell · Medium
Rising heat
About 20 givens — steady killer deduction under pressure.
Enter hellHell · Hard
Serious pain
About 12 givens — advanced cage arithmetic and chains required.
Enter hellHell · Expert
Near the abyss
About 4 givens — expert killer techniques only.
Enter hellHell · Master
Maximum suffering
No givens — only cage sums. Deduce every digit from scratch.
Enter hellKiller 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.
Review classic rulesWhat makes Hell Mode different
Hell Mode is Sudoku Hot’s full Killer Sudoku experience. Every puzzle keeps classic row, column, and box rules, then adds dotted cages with sum clues. That combination rewards careful arithmetic, candidate control, and patience.
How Killer cages work here
Each cage shows a small total in its corner. Digits inside that cage must add up to the total and cannot repeat, even when the cage crosses several boxes. After every cage deduction, classic Sudoku scanning usually reveals new singles.
Start with cages that have very small or very large sums. Those totals have fewer legal digit combinations, so they constrain the grid faster than medium-sized cages.
Choosing a Hell tier
Hell Easy still includes around 28 givens so you can learn cage logic without drowning in candidates. Medium and Hard remove more clues and force longer deduction chains. Expert leaves only a handful of givens, and Master starts blank: only cages guide the solve.
- New to Killer Sudoku? Begin on Hell Easy, then read our Killer Sudoku guide.
- Comfortable with cage sums? Jump to Hard or Expert for longer sessions.
- Want the extreme board? Master is an empty grid with cage totals only.
Hell Mode FAQ
Is Hell Mode the same as Killer Sudoku?
Yes. Hell Mode is Sudoku Hot’s Killer Sudoku board: classic Sudoku rules plus cage sums across five difficulty tiers.
Do mistakes still count in Hell Mode?
Yes. Hell Mode uses the same mistake limits as classic play. A wrong digit can end the run, so treat cage totals as hard constraints.