Skyscrapers is a logic puzzle about a city block seen from the street. Fill the grid with buildings so every row and every column holds each height once, and the clues around the edge say how many buildings you can see looking in from that side. A taller building hides every shorter one behind it.
The rules
Fill every square with a building from 1 up to the size of the grid, so that:
- Every row and every column holds each height once. On a 5×5, that’s 1, 2, 3, 4 and 5 in every row and every column.
- Each clue matches the view. A clue outside the grid counts the buildings you can see looking along that row or column from that side. A building is hidden if a taller one stands in front of it.
Not every row and column has clues, and some puzzles give you a few heights to start with.
Counting the buildings you see
Stand at the end of a line and look along it. The first building always shows. After that, a building shows only if it’s taller than everything in front of it.
What breaks a rule
A clue that isn’t met. This row climbs 1, 2, 3, 4, so all four buildings show from the left, but the clue says 3:
The same height twice in a row or column, just as in Sudoku. In the game, a repeated height turns red, and so does a clue once its line is full and doesn’t match. A clue turns teal when it does.
A puzzle from the game, solved
This is the first level in the game: Easy level 1, a 5×5 with four clues and two heights given.
It takes 23 steps. Here are the first eight.
Steps 1 to 5: a clue of 5
Row 4 has a clue of 5 on the right. All five buildings show from that side, so each must be taller than the one before: reading from the right, 1, 2, 3, 4, 5.
Step 6: a clue of 1
Column 3 has a clue of 1 at the top. Only the first building shows, so it hides all the others: it must be the tallest, 5.
Steps 7 and 8: what column 3 has left
Column 3 now holds a 5, a 4 and a 3, so its two empty squares take the 1 and the 2. Row 2 already has a 2, so its square is the 1, and the last one is the 2.
The rest
From there, it’s mostly counting what each row and column still needs. In all, it takes 6 steps from clues of 1 and 5, 11 where a square has one height left, 3 where a height has one place left, 2 from how far tall buildings must be from a clue, and 1 from listing a row’s arrangements.
Where to start in any puzzle
Look for a clue of 1 (the tallest building stands right next to it) or a clue equal to the size of the grid (the line climbs one step at a time). When there is one, it’s the first move: 36 of the game’s 50 Easy levels have one, 33 Medium and 28 Hard. Otherwise, start from the biggest clues: the tallest building can’t stand close to them.
Common mix-ups
- Hidden buildings don’t count. Only buildings taller than everything in front of them are seen.
- Each clue looks inward from its own side. The same row can show different numbers from its two ends.
- There are no boxes. Unlike Sudoku, only rows and columns have to hold each height once.