What is a word ladder?

A word ladder is a puzzle where you turn one word into another by changing a single letter at a time, and every step along the way must be a real word.

That is the whole game. It takes ten seconds to explain and a lifetime to get good at, which is why it has survived for nearly 150 years under half a dozen different names.

FLOUR→FLOOR→FLOOD→BLOOD→BROOD→BROAD→BREAD

Six moves from FLOUR to BREAD, and every rung in between is a word you already know. Nothing is anagrammed, nothing is added or removed: one letter changes, everything else stays put.

The rules

• Change exactly one letter per move. Not two, not none. The other letters stay where they are.
• Every rung must be a real word. You cannot pass through nonsense to reach something valid on the other side.
• Letters stay in place. Rearranging letters is an anagram, which is a different puzzle. SLATE to STALE is not a legal move.
• Every word is the same length. A ladder from a five-letter word ends at a five-letter word, and every rung between them has five letters too.
• No proper nouns. Carroll's original rules excluded names, and most versions since have kept that.

Lewis Carroll invented it on Christmas Day

The game is the invention of Charles Dodgson, better known as Lewis Carroll, the author of Alice's Adventures in Wonderland. By his own account he devised it at Christmas 1877 to entertain two children who had complained of having nothing to do. He called it Doublets, after the witches' chant in Macbeth: "Double, double toil and trouble."

It caught on quickly. From 29 March 1879 Vanity Fair ran Doublets as a regular competition, with Carroll setting the pairs and readers sending in their ladders. The magazine awarded prizes for the shortest solutions, which makes it, as far as anyone can tell, the first word puzzle with a leaderboard.

Carroll set his doublets in three and four-letter words, which are harder than they look precisely because there are so few of them to move through. His most famous pair asks you to turn FOUR into FIVE:

FOUR→FOUL→FOOL→FOOT→FORT→FORE→FIRE→FIVE

Seven moves, and worth sitting with for a minute: the route goes nowhere near where you would expect, dropping through FOOT and FORT before it finds its way. That detour is the whole pleasure of the game.

He also set HEAD to TAIL, which is gentler:

HEAD→HEAL→TEAL→TELL→TALL→TAIL

And APE to MAN, which is not:

APE→ARE→ERE→ERR→EAR→MAR→MAN

Doublets, laddergrams, word golf

The puzzle has picked up a new name in almost every decade it has survived.

• Doublets is Carroll's own name, and the one you will find in Victorian collections.
• Word ladder is the modern standard, and the metaphor most people find natural: each word is a rung, and you climb from one to the other.
• Laddergrams turns up in mid-century puzzle books, usually for the version with a clue attached to each rung.
• Word golf comes from Vladimir Nabokov, whose narrator in Pale Fire boasts of getting from HATE to LOVE in three. The name stuck because it fits: par is the number of strokes a good player needs, and beating it is the point.
• Word chains is what teachers usually call it, for reasons we will come to.

How to actually get good at them

Most people solve their first few ladders by trial and error, changing letters until something works. That gets you there, slowly. Here is what changes when you have solved a few hundred.

Work from both ends

The single most useful habit. Spend a moment on the target word and ask what could come immediately before it, then do the same from the start. You are looking for a word that both halves can reach, and meeting in the middle halves the search. A ladder that looks impossible forwards is often obvious backwards.

Vowels are the cheap letters

Changing a vowel is usually the safest move available, because the consonant frame around it stays intact and English is generous with vowel swaps: BAND, BEND, BIND, BOND, BUND. When you are stuck, look at your vowels before you touch anything else.

Find the letter that has to change last

In any pair, some positions differ and some do not. The positions that differ have to change at some point, but they rarely change in the obvious order. If a direct swap leaves you with a non-word, that letter probably needs to go last, after the rest of the word has shifted to support it.

Learn the crowded neighbourhoods

Some words have dozens of neighbours and some have almost none. Words built from common consonant frames sit in the busy part of the dictionary and connect to everything, so routing through them is nearly always faster than routing round the edges. A word ending in a rare letter cluster is a cul-de-sac: get out of it early or avoid it entirely.

Going backwards is often forwards

Beginners resist any move that makes the word look less like the target. But the shortest route frequently gets worse before it gets better: Carroll's FOUR to FIVE passes through FOOT, which shares only one letter with the destination. Trust the ladder, not the resemblance.

Why five letters?

Three and four-letter ladders are quick but cramped: there are so few words that most pairs have one obvious route or none at all. Go up to six or seven letters and the dictionary thins out again, leaving long stretches where only one move is legal, which is tedious rather than difficult.

Five is the sweet spot. There are enough five-letter words to make the graph rich, so most pairs have several routes and choosing between them is a real decision, but not so many that anything goes. It is the same reason five letters became the standard for daily word games generally.

It is also why every Break 5 puzzle has a par: the shortest ladder that uses only everyday words, so the target is always reachable with vocabulary you already have. A shorter route sometimes exists through obscure words, and we show you that separately once you have finished, but you are never required to know it.

Word ladders in the classroom

Word ladders have a second life as a literacy tool. Changing one letter at a time forces a child to attend to the sound each letter is doing, which is precisely the skill phonics instruction is trying to build, and it does it in a form that feels like a game rather than a drill. Most primary teachers meet them as word chains, usually with a clue for each rung.

We have free printable word ladders for teachers and parents, with a clue on every rung and an answer sheet.

Play a word ladder now

Break 5 sets one free word ladder every day at midnight UK time, with a leaderboard for the fastest solvers and private leagues if you would rather race people you know. Play today's puzzle, warm up with practice ladders, work through every past puzzle in the archive, or feed two words of your own to the word ladder solver and see the shortest route between them.

New to it? The guided tutorial walks you through a whole ladder one move at a time.