Skyscraping Notation Glossary
Walkthrough Foreword Primer Terminology The Game Plan The Adventure Clueless
Techniques Guesswork, I’m Guessing? Skylining Pencilmarks Haven Couples Pinpoint Firing Range Recursion & Abstraction
Cases Silhouette Stairs Lighthouse Blockade Meet in the Middle Leap of Faith Slide Hideout High-Rise Middle Ground Higher-Rise Successor Outflanked
Showerthoughts The Discrete Difficulty of Size Satisfaction Imagination vs Guesswork Mistakes Nontriviality
Solutions 6x6: Hyperthetical 6x6: The Power of Sudoku 5x5: A Curious Crossways
Info Synopsis FAQ AI decoded Licence

4x4 Puzzles

Setting Out

If you’re looking to start solving Skyscrapers, I think sparse 4x4 puzzles are one of the best places to start.

While you could certainly start by diving straight into 5x5 Skyscrapers (that’s how I started), 4x4s are really great for building intuition and familiarity as a beginner with how all the constraints of Skyscrapers interact.

What Makes 4x4s Great

There aren’t many numbers! You’ve only got {1234}\{1234\}{1234} to worry about, so it’s not overwhelming. And yet you still very much need to use the rules of Skyscrapers to figure out where they all go. For a beginner possibly unaccustomed to logic puzzles, you’re free to focus on the rules and deductions without getting too caught up in the numbers.

3
2
3
31
3
3
13
32
31

9 more cells, a more than 50% larger puzzle, and 1 more digit to worry about (this is greatest difference)!

At the same time, the smaller size of 4x4s also means they have less structure, and you’ll often need pencilmarking to help clue you in to deduction.! This helps you get comfortable with this important habit early on!

34
42
43
4
31
312234
42
23423123
124
31

We’re deducing these candidates by Slide.

And one thing you might notice is that couples come up all the time. Here, we’ve got a pair of [12][12][12]-s eliminating the [23][23][23] to 333, and simultaneously the pair of [23][23][23]-s eliminating the [12][12][12] to 111.

312234
42
342313
124
31

And what’d’y’know, just like that we’ve solved an entire lane relatively effortlessly!

312234
42
34213
124
31

With a little more help from Blockade, we can solve the remaining critical cell.

312234
432
34213
124
31

From here, the rest of the puzzle collapses via Sudoku-style deductions. This usually happens pretty early in 4x4s (since there’s not that much room for complexity), and it’ll train your speed in noticing and executing those deductions!

3122342
432
34213
124
31
31342
432
34213
124
31
31342
4132
34213
24
31
31342
42132
34213
234
31
31342
42132
34213
2134
31

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Last updated 28 April 2026

Skyscraping by Sup#2.0

CC BY-SA 4.0