A short history of the word ladder

The word ladder is older than the computer and older than the crossword. Skyscrapr is a daily version of a puzzle that has been played for nearly 150 years.

Lewis Carroll's doublets

Lewis Carroll said he invented the game on Christmas in 1877, for Julia and Ethel Arnold. His diary first mentions it on 12 March 1878, under the name "Word-links", as a game for two players. He then published a series of puzzles and solutions under the name "Doublets" in the magazine Vanity Fair, starting with the issue of 29 March 1879, and the same year they became a book published by Macmillan.

One of his Vanity Fair puzzles changes HEAD into TAIL in five steps, one letter at a time.

Many names for one puzzle

The same puzzle has also been called word-links, change-the-word puzzles, paragrams, laddergrams and word golf. In his novel Pale Fire, Vladimir Nabokov's narrator uses "word golf" and boasts of records such as hate to love in three moves.

Knuth and the aloof words

The computer scientist Donald Knuth studied five-letter word ladders with a program. He used a collection of 5,757 common English five-letter words and found that 671 of them had no neighbors at all, meaning no other word in the list is one letter away. He called those words "aloof", and noted that "aloof" is itself one of them.

Skyscrapr

Skyscrapr uses four-letter words and gives everyone the same puzzle for a given date. Every puzzle has a known shortest route, shown as the fewest moves. The game is independent and is not affiliated with any other word game.

Sources: Wikipedia, "Word ladder" (en.wikipedia.org/wiki/Word_ladder), read on 2 November 2026. The dates, names and word counts above come from that article, which cites Carroll's own account, his diary and Knuth's study. They were not checked against those primary sources.