How to play Word Ladder: finding the shortest route

Lewis Carroll invented word ladders in 1877, and they still trip people up. These ideas help you see the route instead of stumbling onto it.

The rules

You get a start word and a goal word of the same length. Change exactly one letter at a time, making a real word at each step, until you reach the goal. For example: COLD → CORD → CARD → WARD → WARM.

Count the letters that differ

The shortest possible ladder is at least as long as the number of letters that differ between the two words. COLD and WARM differ in all four letters, so they need at least four steps.

Change one target letter at a time

Each step, try to change a letter into the one it needs to become. If that makes a real word, you’ve made progress. If not, try a different position.

Vowels are bridges

Changing a vowel often opens up words that consonant changes can’t reach. If you’re stuck, try swapping the vowel: BAT → BIT → BIG.

Sometimes step sideways

Occasionally you need to change a letter that already matches, or change a letter to something that isn’t in the goal, to get around a blocked route. It costs a step but can save several.

Work backwards

Look at the goal word and think of words one letter away from it. If one of those is easy to reach from where you are, you’ve found your route.