Change one letter at a time to transform the start word into the target word, using only valid words of the same length without repeating any
Welcome to the deceptively challenging world of word ladders. Although they seem simple, word ladders challenge you, forcing you to use logic and strategy, working far more of your brain than you might expect. The rules are simple, but the solutions can be anything but.
Like many of the best puzzles, the rules are simple and easy to pick up.
Using our example, in four steps, you could go:
One of the challenges is that there are often multiple ways to complete a puzzle. You might also go:
The best way to learn, though, is to solve a few yourself. Why not try some puzzles on this site, or read on to find out more about word puzzles, why they are so popular, and the benefits you can get from spending just a few minutes pondering which letters you can change?
The invention of word ladders is credited to Lewis Carroll — best known for writing Alice's Adventures in Wonderland and Through the Looking Glass. Carroll invented the game for friends in 1877, writing about it in his diary a few months later.
Calling his game 'Doublets', he originally envisaged it as a two-player game, with partners taking it in turns to move the word closer to the target word.
From that small start, with just a few friends playing, the popularity of word ladders soon grew. Within a couple of years, Carroll was contributing the puzzles to Vanity Fair. Starting in March 1879, they became a regular feature in the magazine, and the puzzle soon established itself.
The puzzles have been called different names over the years. Carroll's original name, Doublets, is rarely used, but other names, like word links or word chains, have become more popular. However, they are most commonly known by the name 'word ladders', mainly because they are usually presented in a vertical grid that resembles a ladder.
The simplicity of the basic game has meant that it's easy to create variants with additional rules.
Most word ladders use four-letter words. However, some puzzles use five-letter words. There are some who feel that this provides more of a challenge, but others suggest that the more limited options make longer words easier. Indeed, word ladders with six letters or more are rare because of the limited solutions they offer.
Lewis Carroll's original problems used start and end words that have a connection. The earliest he is known to have created was an opposite: HEAD → TAIL (HEAD → HEAL → TEAL → TELL → TALL → TAIL). But other puzzles may be synonyms, like GOOD → FINE (GOOD → FOOD → FOND → FIND → FINE), or just words that have a relationship, like BALL → KICK (BALL → BALK → BACK → SACK → SICK → KICK).
Some word ladders provide clues. This means that multiple solutions are not possible, but instead that each step must meet the rules of word ladders and match the clue. Let's try one:
The shortest word ladders are already solved. These single-step word ladders only need a single letter change, like CAT → MAT. In most word ladders, the shortest route will be the same as the number of letters that have changed, which is why four-letter word ladders are often four steps long. However, deliberately long word ladders, using obscure words with limited options, can stretch some four-letter ladders to over 100 steps.
If you see a word ladder with ALOOF, don't even try to solve it. Mathematician Donald Knuth analysed five-letter word ladders with common words. He discovered 671 words, including ALOOF, that could not be changed. He named the whole group 'aloof words' because they stayed away from all the others.
We overlook shorter words when we consider our vocabulary — and the very phrase 'four-letter word' is frequently used to refer to foul language. But playing word ladders might help you expand your vocabulary. Far from being a peon of your communication, they can take up the yoke, and may even oust some longer words you are wont to use.
Whether you are a native English speaker or learning it, word ladders can help. The changes at each step are small, but the difference it makes to the word, both in meaning and pronunciation, can be big. Speaking the words in the ladder, while noting the changes in letters, is a good way to learn the phonics of English and develop an ear to distinguish similar sounding words.
Like many puzzles, the simplicity of word ladders hides the many benefits they offer.
Word ladders may be one of the best puzzles you can do. Simple to understand, enough of a challenge to be worthwhile, and wrapped up in a little brain workout.
Try one todaySee for yourself how much fun climbing those ladders can be.