Skyscrapers Puzzle (Apartments Game) — Complete Guide and Difficulty Levels

The Skyscrapers Puzzle, also called the Apartments Game, combines the logic of Sudoku with a unique visual challenge. In this guide you’ll learn how the puzzle works, how difficulty is measured, and what strategies help you solve it efficiently. play online for free.

What Is the Skyscrapers Puzzle?

The Skyscrapers Puzzle is a logic puzzle in which you fill a square grid with numbers from 1 to N. Each number represents a building height — higher numbers mean taller buildings. Around the grid, small clues indicate how many buildings are visible from that direction. A tall building hides any smaller buildings behind it, just like a real skyline.

The challenge is to make sure every row and column contains all numbers once, while every side clue matches the number of visible buildings. This requires visual reasoning, deduction, and careful elimination rather than guessing.

Basic Rules — Step by Step

Each row and column must contain all numbers from 1 to N with no repetition.
The numbers represent the building heights — larger numbers mean taller buildings.
Edge clues tell you how many buildings are visible from that side.
Taller buildings block smaller ones behind them.
The puzzle must satisfy both uniqueness and visibility constraints.

For example, if a 4×4 puzzle has the clue “2” on the left, exactly two buildings must be visible from that direction. Usually this means one smaller building followed by a taller one like 1-3-4. These logical visibility patterns form the foundation of the solution.

Difficulty Levels (Practical Reference)

Ozerlyn classifies Skyscrapers puzzles by the depth of logical reasoning required, not just the number of clues. The following guide helps you choose your level:

Beginner (0–1.5)

Simple placements from single clues. Great for learning the visibility concept.

Easy (1.6–3.0)

Basic cross-analysis between opposite clues. Smooth and logical once familiar.

Medium (3.1–5.0)

Partial visibility combinations and methodical note-taking required. Great mental exercise.

Hard (5.1–8.0)

Advanced logical chains, multi-directional reasoning and visual contradictions.

Expert (8.1–12.0+)

Deep multi-step reasoning, evaluating multiple perspectives simultaneously — for true logic masters.

Remember: difficulty depends on how clues interact logically, not on how many are visible.

Solving Strategies and Tips

Start with the smallest clues: they usually reveal the tallest buildings first.
Use cross logic: combine opposite clues to limit possible heights.
Take notes: jot down small possible numbers in each cell to catch contradictions early.
Watch the corners: edge intersections often hold the key to unlocking the puzzle.
Look for symmetry: many well-designed grids have mirrored logic patterns that speed up solving.

Skyscrapers Puzzle — Frequently Asked Questions

What is the Skyscrapers Puzzle?

A logic puzzle where you place buildings of different heights while following visibility clues from all sides.

What grid sizes exist?

Usually 4×4, 5×5, 6×6, or 7×7. Larger grids increase complexity.

How is it different from Sudoku?

Sudoku uses symbolic constraints, while Skyscrapers relies on visual clues — training both logic and spatial reasoning.

Can I play it for free?

Yes. Play online at Ozerlyn Skyscrapers or

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Skyscrapers Puzzle Game: Rules, Tips, and Mental Benefits