Skyscrapers

Skyscrapers is a Latin-square deduction puzzle. Place a height from 1 to N in every cell so no height repeats in any row or column. The numbers around the outside tell you how many buildings are visible looking down that row or column from that side, a taller building always hides any shorter ones behind it.

• A clue of 1 means the tallest building (N) sits right at that edge.
• A clue of N means the buildings climb in perfect order from that side.
• A clue glows red once its line is full but the visible count is wrong; the grid completes when every row, column and clue is satisfied.

• Desktop: click a cell, then type a height (1–N) or click the on-screen number pad. Use the arrow keys to move, Backspace to clear, and P to toggle pencil marks for candidates.
• Phone & tablet: tap a cell, then tap a number on the pad; tap the erase key to clear, no keyboard needed.

• Sizes, 4×4, 5×5 and 6×6 grids for a gentle warm-up through to a real workout.
• Daily, one shared puzzle each day for everyone.
• Practice, fresh random puzzles on demand.

• Start with the extreme clues: a 1 forces the tallest building at the edge, and a clue equal to N fixes the whole line.
• A clue of 2 next to the edge usually means the second cell is the tallest, pencil in what each edge rules out.
• Cross-reference rows and columns constantly; a height placed for one clue often resolves another.

Skyscrapers has no attributable origin, and belongs instead to the large family of Latin square puzzles — grids in which every symbol appears exactly once per row and column.

Sudoku is the famous member of that family and futoshiki a closer relative, since both replace the Latin square's blank starting grid with a different kind of external constraint. Sudoku adds boxes and givens; futoshiki adds inequalities between neighbours.

What this puzzle adds instead is a viewpoint. The numbers around the edge count how many buildings are visible from that side, with taller ones hiding shorter ones behind them — so a clue of 1 means the tallest building stands first, and a clue equal to the grid size forces a strict ascending run. The constraint is about occlusion, which no other member of the family uses.

Skyscrapers is a visibility twist on Latin-square and sudoku-style logic, where edge clues replace given digits. This is an original, free browser version with daily and practice puzzles, playable instantly with no download or sign-up.

A free, original browser game on PlayPendium. No download, no install.