Word Ladder Guide: Solve in Par Every Time

Count what has to change

Before anything else, compare the start and goal letter by letter. Each position that differs must change at least once, so the number of differing positions is the minimum number of steps. COLD and WARM differ in all four positions, so the ladder cannot be shorter than four. If the par equals the number of differing letters, the ideal route changes each letter exactly once and never touches a letter that is already right. If the par is higher, at least one letter must change twice, usually because a direct route passes through a non-word.

This gives you a plan: for each differing position, you need a rung where that letter switches. The order is the whole puzzle.

Work from both ends

Most solvers start at the top and push forward. Working backward from the goal is just as valid and often easier, because the goal word may have very few neighbours. List the words one letter away from the goal, and the words one letter away from the start, and look for a pair that are one letter apart. Meeting in the middle halves the search.

Change the vowel first

In four- and five-letter words the vowel is the hinge. Changing a consonant often produces a non-word, but swapping the vowel in a common frame (B_T, C_T, P_N, L_ST) almost always does. When you are not sure where to go, change the vowel to one that fits the goal and see what consonants that frame allows. Frames with many vowel options (b_t: BAT, BET, BIT, BOT, BUT) are junction words: routes pass through them.

Bridge words and dead ends

Some words have many neighbours and some have almost none. Words with rare letters (QUIZ, JINX) or awkward clusters tend to be dead ends: you can reach them but not leave. Words made of common letters in common frames (CARE, LINE, POST, HAND) are bridges with a dozen neighbours each. When choosing between two possible rungs, choose the one with more ways out. If you find yourself at a rung with no next step, Undo takes you back one step at a time; use it rather than starting over.

Keep the right letters fixed

Once a letter matches the goal, try never to change it again, unless the par tells you that something must change twice. A classic beginner's loop is changing a correct letter to escape a dead end and then changing it back, which costs two steps. If the only way forward changes a correct letter, that is a sign you took a wrong turn one or two rungs earlier.

Typing and tapping

You can type a whole word and press Enter, or tap the letter of your next word that you want to change and type the replacement. Tapping a single letter is faster and stops you accidentally changing two letters at once, which the game would reject. The par is shown from the start, and the leaderboard ranks by fewest steps, then time, so a route one step over par with no wasted time still ranks well.

A method in five steps

1. Write the start and goal one above the other and mark the positions that differ.
2. Note the par. If it equals the number of differing positions, plan to change each once.
3. List the neighbours of the goal; these are the words you must arrive at.
4. From the start, change the letter that produces the word with the most neighbours, preferring the vowel.
5. Aim for a word one step from the goal's neighbours, and finish.

Common mistakes

• Changing two letters at once. Every rung changes exactly one.
• Guessing rungs that are not words. Proper nouns and abbreviations are refused; think of ordinary words.
• Working only forward. The goal often has the fewest neighbours, so start there.
• Touching letters that already match. Each unnecessary change costs at least two steps.
• Starting over instead of undoing. Undo removes one rung; the earlier rungs were probably fine.

Glossary

• Rung: one word in the ladder.
• Par: the fewest steps in which the ladder can be solved.
• Neighbour: a word one letter different from another.
• Frame: a word with one letter blanked (C_T), used to find neighbours by trying letters in the blank.
• Bridge word: a word with many neighbours that routes pass through.