Skyscraper Sudoku
Outside clues show how many 'buildings' are visible from that edge
Skyscraper Sudoku is fully playable. Choose a difficulty and start solving.
Treat digits as building heights: each outside clue counts how many buildings are visible from that edge, taller ones hiding everything behind them. A clue of 1 plants a 9 immediately; a clue of 9 forces a fully ascending line. Permutation reasoning layered onto Sudoku — heavier than it looks.
For the complete rules, worked examples and solving techniques, read the full How to Play Skyscraper Sudoku guide.
Like all Sudoku variants, Skyscraper Sudoku 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 |