Sukaku
A pencilmark-style variant where clues are given as candidate sets
Sukaku is fully playable. Choose a difficulty and start solving.
Every cell opens pre-loaded with printed candidate marks and not a single confirmed digit. Solving is pure elimination — whittle each cell down until one possibility survives. It plays like joining a classic puzzle mid-solve, with the bookkeeping handed to you.
For the complete rules, worked examples and solving techniques, read the full How to Play Sukaku guide.
Like all Sudoku variants, Sukaku builds on the classic 9×9 foundation. Every row, column, and 3×3 box must contain each digit from 1 to 9 exactly once. The variant constraint is added on top of these standard rules, never replacing them.
If you're new to Sudoku, start by learning the basic rules and techniques before attempting variants.
Techniques Useful for This Variant
| Technique | How it applies |
|---|---|
| Pencil Marks / Notes | Essential for tracking candidates alongside the variant constraint |
| Obvious Singles | Cells narrowed to one candidate by the combined constraints |
| Hidden Singles | Digits with only one valid cell in a unit after variant elimination |
| Pairs and Triples | Locked candidates exposed by the additional constraint |