Word ladder

A word ladder is a puzzle in which you change one word into another by altering a single letter at each step, so that every step in between is also a real word.

Turn COLD into WARM, one letter at a time, with a real word at each step.

COLD CORD CARD WARD WARM

Four steps, each changing a single letter. That is a word ladder.

The rules

• Change exactly one letter at each step.
• Every step must be a real word.
• You may not rearrange the letters.
• A shorter ladder is a better one.

Lewis Carroll invented the puzzle in 1877 and called it Doublets. His classic is HEAD to TAIL: HEAD, HEAL, TEAL, TELL, TALL, TAIL.

Tips for solving

• Work from both ends. Find words reachable from the start and words that lead into the end, and look for a match.
• Use common patterns. Three-letter and four-letter words with -AT, -AN, -ET or -IN endings are well connected.
• Change vowels. They often open new routes when consonant changes dead-end.
• Try a different path. If the direct route fails, step sideways to a word with many neighbours.

Why it matters to a writer or editor

A word ladder is a lesson in how words relate by shape. It sharpens spelling and builds vocabulary, which is why teachers set it as a classroom game. It also shows how much of English sits in small clusters of look-alike words, the same clusters that cause typos. A proofreader who has played a lot of word ladders sees near-misses on sight. Related puzzles include the anagram, which rearranges letters, and the crossword.

Frequently asked questions

Who invented the word ladder?

Lewis Carroll, who called it 'Doublets' and published the first one in Vanity Fair in 1879. His famous example turns HEAD into TAIL.

What are the rules?

Change exactly one letter per step. Each result must be a valid word. You cannot rearrange letters, and the aim is to reach the target word in as few steps as possible.

How do you solve one?

Work from both ends. Look for common middle words that bridge the two, and prefer changes that keep the letters of common words such as -AT, -ET or -IN endings.