The numbers around the edge tell you how many towers you can see when you look along that row or column from that side. Taller towers hide shorter ones behind them.
Skyscraper rules in 30 seconds
- 1Fill every cell with a height from 1 to N.
- 2Each row and column contains each height exactly once.
- 3An outside clue is how many towers are visible from that side.
- 4A taller tower hides every shorter tower behind it.
See it on a board
Watch: how to play Skyscraper
Still not sure? Some puzzles click faster when you see them solved. This 13-minute video from Steven Scott shows Skyscraper in action.
Counting visible towers
Look along the row 1, 3, 2, 4 from the left. You see the 1, then the 3 (taller), the 2 is hidden behind the 3, then the 4 (taller again). That's three visible towers, so the left clue is 3. From the right you only see the 4, so the right clue is 1.
The clues that solve themselves
- Clue 1: the tallest tower (N) is right next to that edge.
- Clue N: the towers rise 1, 2, 3 … N in order from that side.
- Clue 2: the first tower isn't N, and nothing between it and N is taller than it.
- A blank clue means no information from that side.
Opposite clues work together
The tallest tower is visible from both ends of its line, so the left and right clues of a row can never add up to more than N + 1. When they add up to exactly N + 1, the tallest tower sits exactly that many cells in from the left, and the towers rise in order toward it from both sides.
On a 5×5, a row with clues 2 and 4 (2 + 4 = 6 = N + 1) puts the 5 in the second cell from the left, with the other towers climbing toward it from the right.
Worked example
- 1On a 4×4, a row has a 1 on the left and a 2 on the right.
- 2Clue 1 puts the 4 in the leftmost cell.
- 3From the right you must see exactly two towers: the nearest one, then the 4. So the rightmost tower must be taller than the two cells between them.
Skyscraper tips and strategies
Place the tallest first
Clue 1s and clue Ns place N-height towers instantly.
Read opposite clues together
A row's left and right clues constrain the same cells from both ends.
Big clues mean small starts
A high clue means the first tower from that side must be short.
Use Notes
When a cell could take two heights, note both and let the crossing line decide.
Common mistakes to avoid
- Counting hidden towers as visible.
- Forgetting the row-and-column no-repeat rule while chasing clues.
Play Skyscraper in 10+ Number Puzzles
- Tap a cell to outline it and highlight its row and column.
- Notes switch the number pad to candidates.
- Pausing saves your progress, notes, time and selected cell.
- You have 3 lives. A wrong height costs one.
- Five difficulty levels, each a ladder of stages from Easy to Genius.
- Go online for free: ranked 1v1 duels, rooms where you race, co-op or play in teams, and tournaments.
- 27 more puzzle types in the same app, and online play never costs coins.
Skyscraper FAQ
What does a clue of 1 mean in Skyscraper?
Only one tower is visible, so the tallest tower must be right next to that edge.
What does a clue equal to the grid size mean?
Every tower is visible, so heights increase one by one from that side.
Is Skyscraper like Sudoku?
It shares the no-repeat rule for rows and columns, but has no boxes and uses visibility clues instead of given numbers.
