The History of Skyscrapers
Skyscrapers belongs to the same family of Latin-square puzzles Sudoku comes from, but adds a distinctive twist that gives it its name: a line-of-sight rule read in from just outside the grid.
Puzzle-Magazine Roots
Unlike Sudoku, Skyscrapers has no single, well-documented inventor or first publication date that historians agree on. Like many logic-puzzle genres, it seems to have emerged and spread gradually through puzzle-magazine culture rather than being credited to one named creator at one particular moment - the visibility-clue idea is simple enough that more than one puzzle constructor plausibly arrived at it independently.
What is certain is the mathematics underneath it: like Sudoku, a solved Skyscrapers grid is a Latin square - a grid where each symbol, here a building height, appears exactly once per row and column - an object studied by Leonhard Euler in the 18th century, long before either puzzle existed.
A Competition Puzzle
Skyscrapers found its widest international audience through competitive puzzling, especially the World Puzzle Championship, an annual international puzzle competition first held in 1992, where it is one of many recurring standard genres alongside the Sudoku family and other Latin-square-based puzzles.
That competition setting helped settle the puzzle's rules and presentation into the standard form played today, even without a single credited inventor - much the way several recurring puzzle genres owe their final shape less to one creator than to repeated use in puzzle magazines and championship puzzle sets.
Latin Squares, Viewed From Outside
What makes Skyscrapers conceptually distinctive is how it layers a spatial, visual idea - looking along a line of buildings and counting how many are tall enough to be seen - on top of logic already familiar from Sudoku's rows and columns. That combination is also exactly what gives the puzzle its name and its thematic presentation, unlike the plain grid of digits a Sudoku or a bare Latin square puzzle presents.
It's also exactly the property PaperGames's generator relies on in reverse: since an edge clue is really just a fact computed from a finished grid, every puzzle here is produced by building a full valid grid first, computing every possible clue from it, and then keeping only as many of those clues as still pin the grid down to a single unique solution - the same generate-then-reduce approach this collection's Sudoku and Kakuro generators use, adapted to a different constraint.