Word Ladder

How to play Word Ladder

Word Ladder is a classic English word puzzle: you turn a START word into a TARGET word by changing a single letter at a time, and every word you make along the way must be a real word of the same length. The puzzle was invented by the author Lewis Carroll, who called it “Doublets”, and it has entertained puzzlers for nearly 150 years. It is wonderfully simple to learn — anyone who can read can play — yet finding the shortest ladder can be a real brain-teaser. This version gives you three word lengths, a live word-checker, an optional hint, an undo button and a leaderboard, so you can race for a high score or just enjoy the climb.

The goal

You are shown two words of the same length: a start word at the bottom of the ladder and a target word at the top. Your job is to transform the start word into the target word one rung at a time. On each rung you change exactly one letter of the previous word to make a brand-new valid word, keeping all the other letters in place. When the word you make is the target word, the ladder is complete and you win. The game also shows the “best possible” number of steps — the length of the shortest ladder — so you always know how close your solution is to perfect.

A little history: Lewis Carroll’s “Doublets”

Word Ladder was created by Charles Lutwidge Dodgson — better known by his pen name Lewis Carroll, the author of “Alice’s Adventures in Wonderland”. He invented the game for two bored young friends at Christmas in 1877 and named it “Doublets”, after the witches’ chant “Double, double toil and trouble” in Shakespeare’s Macbeth. Carroll published the puzzle in the magazine Vanity Fair in 1879, complete with rules and a scoring system, and even printed a small booklet of them. He called the start and finish words the “doublet”, the words in between the “links”, and the whole sequence a “chain”. Over the decades the game has been known by many names — Word Ladder, Word Golf, Laddergrams and Stepwords — but the idea has never changed. Because Carroll’s puzzle is well over a century old, it is in the public domain, and this is an entirely original re-creation with our own word list.

Setting up a puzzle

Pick a difficulty, which sets the word length: Easy uses 3-letter words, Medium uses 4-letter words and Hard uses 5-letter words. Tap New Puzzle and the game chooses a start and target pair for you. Every pair is generated to be solvable: behind the scenes the game runs a breadth-first search across the whole word graph, so it only offers you a target it can actually reach from the start, and it records the exact length of the shortest ladder. That means there is always a solution — no puzzle is ever a dead end.

The rules

• Change exactly one letter at each step. You may not change two letters at once, and you may not leave the word unchanged.
• Keep the same length. Letters are never added or removed, so every word on the ladder has the same number of letters as the start and target.
• Every rung must be a real word. The word you type has to appear in the game’s dictionary; nonsense letter strings are rejected the moment you type them.
• You may not rearrange the letters. Only substitution is allowed — you swap one letter for another in its place, you never shuffle the order of the letters.
• Reach the target word to win. You can take any valid route you like; when the newest rung equals the target, the ladder is complete.

Difficulty and ladder length

Difficulty combines two things: how long the words are and how far apart the start and target sit. Easy puzzles use 3-letter words with a short shortest-ladder (about two to four steps). Medium puzzles use 4-letter words spread a little further apart, and Hard puzzles use 5-letter words that can be five or more steps apart. Longer words have fewer neighbours that differ by a single letter, so the higher levels ask you to plan more carefully and think several rungs ahead.

How scoring works

When you solve a puzzle you earn points, and higher is better. Each difficulty starts from a base budget — 2000 for Easy, 4000 for Medium and 6000 for Hard — and finishing adds a solved bonus of 400, 800 or 1200. From that total the game subtracts one point for every second you took, 50 points for each extra step beyond the shortest possible ladder, and 150 points for every hint you used. The result is clamped so it never drops below 1 and never exceeds 99,999. In short: solve quickly, take the shortest route and avoid hints to top the leaderboard.

Winning, undo and hints

The moment your ladder reaches the target word, you win and your score is shown and submitted to the leaderboard. If you take a wrong turn, the Undo button removes your last rung so you can try a different letter — undoing does not cost anything, but the clock keeps running. If you get truly stuck, the Hint button adds the next word from an optimal shortest ladder for you; it always makes progress toward the target, but each hint lowers your score, so use them sparingly.

Strategy tips

• Compare the two words letter by letter first. The positions that already match usually want to stay the same, and the positions that differ are the ones you will eventually have to change.
• Change the “easy” letters early. Vowels and common endings often have many one-letter neighbours, so switching them first tends to keep more options open than changing an awkward consonant right away.
• Think of common word families as stepping stones. Short rhyming groups such as CAT–COT–COG or COLD–CORD–WORD let you slide between shapes quickly.
• Watch the “best possible” number. If your step count climbs well above it, you may be wandering; undo a rung and look for a more direct route.
• Do not fixate on fixing the first differing letter immediately. Sometimes you must temporarily change a letter that already matches the target in order to reach a valid in-between word.

Frequently asked questions