How to Play Skyscrapers

Overview

Skyscrapers (also known as "Towers") is a logic puzzle where you fill a grid with buildings of different heights. The clues around the edges tell you how many buildings are visible when looking from that direction. Taller buildings block shorter ones behind them, just like real skyscrapers!

Video Tutorial

Rules

  • 1Fill the NxN grid with numbers 1 to N (for a 4x4 puzzle, use numbers 1-4).
  • 2Each row must contain each number from 1 to N exactly once.
  • 3Each column must contain each number from 1 to N exactly once.
  • 4Clues around the edges indicate how many skyscrapers are visible from that direction.
  • 5A taller skyscraper blocks the view of all shorter skyscrapers behind it.

Understanding Visibility

Imagine standing at the edge of the grid and looking across the row or column. You can only see a building if no taller building is in front of it.

4
1-2-3-4
All 4 visible (ascending order)
1
4-?-?-?
Only 4 visible (4 blocks everything)
2
3-4-?-?
3 visible, then 4 (which blocks rest)

Controls

Drag & DropDrag numbers from the pool onto empty cells
Click CellSelect a cell, then click a number to place it
Click FilledClick a filled cell to remove the number
Ctrl+ZUndo last move

Solving Strategies

Edge Clues of N

A clue equal to the grid size (e.g., 4 in a 4x4) means buildings must be in ascending order: 1, 2, 3, 4. Only one arrangement works!

Edge Clues of 1

A clue of 1 means the tallest building (N) must be right next to that edge - it blocks all others.

Use Both Ends

Look at clues on opposite sides of a row/column together. For example, clues of 2 and 3 greatly limit possible arrangements.

Start with Extremes

Clues of 1 and N are the most restrictive. Find where the tallest building must go first.

Latin Square Rules

Remember: like Sudoku, no number repeats in any row or column. Use elimination to narrow down possibilities.

Work Both Directions

If you know a building's height, check how it affects visibility from both ends of its row and column.

Example

Consider a row with a "4" clue on the left and "1" on the right in a 4×4 puzzle:

  • The "4" means all buildings must be visible from the left → they must be in order: 1, 2, 3, 4
  • The "1" confirms this: only the 4 (rightmost) is visible from the right
  • This row is completely determined: 1 2 3 4