Letter & number codes

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A code is a secret way of writing. There is always a rule, and once you find the rule you can read anything. Each puzzle gives you one example to show you the rule. Your job is to spot it, then use it.

First, the tool you will use most: the alphabet, with each letter’s position number underneath. You count along it to see how far a letter has moved.

For example, A is 1 and D is 4, so going from A to D is 3 steps forward. Going from D back to A is 3 steps back. That counting is the heart of nearly every puzzle here.

There are three kinds of code below. Each one starts with a short explanation and a worked example, then lets you try it.

• Letter codes — the letters of a word slide along the alphabet, or mirror to the opposite end.
• Letter connections — a pair of letters changes into another pair.
• Word-number codes — each letter is a number, and you match words to their codes.

1. Letter codes

In a letter code, every letter of a word changes to make the code. To find out how, line the word up with its code and look at each letter in turn. Here are the patterns to watch for.

• The same jump every time. Every letter moves the same number of steps, for example 3 forward.
• A growing jump. The steps get bigger as you go: the 1st letter moves 1, the 2nd moves 2, the 3rd moves 3, and so on.
• Going backwards. Letters can move back towards A instead of forward. Forwards adds, backwards takes away.
• Falling off the end. If you move past Z, loop back to A. Past A, loop back to Z. So Z moved 1 forward becomes A.

A different kind: mirror codes

Some codes do not slide at all. Instead, each letter flips to its partner at the opposite end of the alphabet. A swaps with Z, B with Y, C with X, and so on. Here is every mirror partner:

How do you spot a mirror code? The jumps will not be equal, and you will see letters near the start of the alphabet swapping with letters near the end. When that happens, use the mirror strip above to read off each partner.

2. Letter connections

Here you are shown two letters that turn into two other letters, like “AC is to BD.” The clever part is that each letter can move in its own way. So you work out what happens to the first letter, then to the second letter, then do the very same moves to a new pair.

Use the alphabet strip to count each move. The two letters might move by different amounts, or even in different directions, one forwards and one backwards.

3. Word-number codes

In these, every letter is given a secret number, and the same letter always gets the same number. You are shown some words and their number codes, but the codes are jumbled, so you have to match them up.

The way in is to look for words that share letters. Two words made of exactly the same letters (just in a different order) will have exactly the same digits, in a different order. A word that shares only some letters will share only some digits. Start by spotting those.