Invent a Cipher

Your child invents their own secret code, uses it to write a short message, and then challenges the family to crack it. A puzzle-making game about patterns and logic.

How to do it

1. Show your child one simple code idea, such as shifting every letter along by three or swapping each letter for a symbol.
2. Let them invent their own code, writing out the key that maps each normal letter to its secret version.
3. Have them use the key to write a short secret message, checking each letter against the key.
4. Ask them to hand over the coded message, with or without a hint, and challenge the family to crack it.
5. Once someone cracks it or gives up, have your child reveal the key and talk about what made it easy or hard.

What you need

• Paper
• Pencil or pen
• Key sheet

Make it yours

Younger, 6 to 8 years: Use a picture-symbol code for a short word rather than a full letter shift. Older, 10 to 12 years: Try a keyword cipher or add numbers, and time how long the family takes to crack it. Siblings: Two children invent codes and swap messages to crack each other's