Skyscrapers
Build a city grid where the edge numbers tell how many towers you can see.
How to play Skyscrapers
Skyscrapers is a number puzzle for one player. The grid is a small city seen from above. Every square holds one tower, and its number is the tower's height in floors. The numbers around the edge tell you how many towers a person standing there can see.
Goal
- On a 5×5 grid, use the heights 1 to 5. On 6×6 use 1 to 6, and on 7×7 use 1 to 7.
- Each row and each column holds every height exactly once.
- A number on the edge says how many towers are visible from that side, looking along the line. A taller tower hides all the shorter towers behind it.
For example, the row 2 1 4 3 shows 2 towers from the left (the 2 and the 4) and 2 from the right (the 3 and the 4). Some puzzles also give a few heights in the grid to start with. Every puzzle has exactly one answer.
Step by step
- Select a square by tapping it or by moving with the arrow keys. Its row, column and edge numbers light up.
- Enter a height with the number pad or the number keys. Each filled square shows a small tower, so the skyline is easy to read.
- Turn on Notes (or press N) to write small pencil marks for heights that could fit.
- Use Erase or Backspace to clear a square, and Undo to go back.
- A height used twice in a line turns red. When a line is full, its edge numbers fade if they match and turn red if they do not.
Levels
Easy is 5×5 with most edge numbers shown. Medium is 6×6 with about half the numbers. Hard is 7×7 with only the numbers you really need.
End of the game
The puzzle is solved when every square is correct. The timer stops and shows your time, and your progress is saved in this browser until then. If you enjoy number grids, try Sudoku or Futoshiki.
Strategy tips
- A 1 means the tallest tower is first. If you can see only one tower, the highest one stands right next to that number.
- The top number is a staircase. If the clue equals the grid size, the line rises one floor at a time: 1, 2, 3 and so on.
- Big clues push tall towers away. With a clue of 4 on a 5×5 grid, the 5 can only stand in the last two squares from that side.
- Read both ends together. Opposite clues that add up to the grid size plus one leave very few places for the tallest tower.
- Place the tallest towers first. Each line has one tower of the top height. Find its spot, and the rest of the line becomes clearer.
- Use notes on hard grids. Write the possible heights in each square and remove them as the rows and columns fill.
Skyscrapers FAQ
What does the number on the edge mean?
It counts the towers you can see from that spot when you look along the row or column. A tower is hidden if a taller one stands in front of it.
Why are some squares filled at the start?
On bigger grids, the edge numbers alone sometimes allow more than one answer. A few given heights make the solution unique.
Does every puzzle have only one answer?
Yes, a solver checks each one. Easy and Medium can always be solved step by step from the clues. Hard puzzles may also ask you to test an idea and follow where it leads.
Is this like Sudoku?
A little. Like Sudoku, each row and column uses every number once, but there are no boxes and the clues are views from the edge instead.
