Secret code for kids

Secret code ideas for kids

Secret code ideas are multiple and have existed for thousands of years. Kings already used written messages to give orders, but since these had to remain secret, they used coded messages. Indeed, to establish the plans of attack of his armies for example, it was better that the message remained confidential. Only close collaborators could decipher them, and the enemies understood absolutely nothing about them.

We are going to show you different types of easy-to-use secret codes. Children love them. They’re a must for an activity such as a treasure hunt.

Discover all our treasure hunts for kids to play at home.

Treasure hunt for kids


  1. Invisible ink
  2. Pinprick Cipher
  3. Cardan Grille Cipher
  4. Acrostic Cipher
  5. Say the opposite of what we want to say
  6. Zig Zag Cypher
  7. Block Cipher
  8. Reverse Alphabet
  9. Morse Code
  10. Caesar Cipher
  11. The backwards sentence
  12. The mirror sentence
  13. Pigpen Cipher
  14. The Dancing Men
  15. Tap Code
  16. Letters as drawings
  17. Replace one word with another
  18. A few tips to make your secret code

1- Secret Code: invisible ink

Here is a secret code that works very well with children and is simple to implement. It is the invisible ink: for this you will only need a lemon! The method is simple… Take a cotton swab and soak it in the lemon juice that you will have previously pressed. Then, on a white sheet of paper, write your text using the cotton bud soaked in lemon. Of course, you can’t see anything! If the message is intercepted, no one will be able to decipher it. The recipient of the message must then iron the sheet with a hot iron. The message will then appear as if by magic.

2- Pinprick Cipher

Hide your message in a newspaper article or in banal text and no one will be able to imagine that a message is hidden inside. There is a method invented by the Greeks more than 2400 years ago: pinpricks.

Indeed, it is enough to write an ordinary text and under certain letters, make a tiny hole with a pin. Thus, the person receiving the message has just looked at the letters that are punched and reconstruct the word.

secret code: pinprick cipher

3- Cardan Grille Cipher

Write a very ordinary text and prepare a cache that will be cut out on certain areas. When the cache is applied to the letter or sheet, then only certain words will be visible. You will then just have to read them to get the message.

By placing the cache on the letter, the words of the coded message will appear in the openings.

secret code for kids: cardan grille cipher

4- Acrostic Cipher

Do you know how this secret code works? Write a text and a secret will be hidden in it. So how do you discover it? Just take the first letter of each line. You will then get a word or a sentence. Of course, you can vary and use the second, third or even last letter. For a long sentence to code, you can use the first word of each sentence in a text for example.

5- Say the opposite of what we want to say

Start by thinking about the message you want to write with 2 or 3 simple sentences. Then put these sentences in negative form… Then insert these sentences in a text so that these negative sentences go unnoticed. To decipher the message, the child will have to look for only the negative sentences and then put them back to the affirmative form…

6- Zig Zag Cypher

Here is a secret code very simple to realize. Prepare your coded message. Take a sheet of paper and write it on 2 lines: the first letter on the top line and the second on the bottom line and so on without interruption until the end of the sentence, alternating top and bottom line for each letter. Then copy the 2 lines obtained on a paper one after the other by separating them by a dash. You get your coded message.

So, to decode them, the child will in turn have to write the first word obtained on one line and the second word after the dash on a line below and read the message in zig zag.

secret code: zig zag cipher

7- Block Cipher

Use a grid in the form of a table for example 5 X 5 boxes (more or less depending on the length of your message).

The author will write his message in the boxes from left to right but without making spaces with one letter per box. Once this step is completed, you just have to take a sheet of paper and copy the letters but this time writing them one column after the other and from top to bottom. Place a dash at the end of the first column before moving on to the second and so on. The receiver will then have to count the number of letters to know the number of cells in the table … He will then trace a table of the corresponding size. He will write the letters of the message from top to bottom starting from the first column. Once the message has been completely rewritten, he will be able to read it in the lines from left to right.

secret code for kids: block cipher

8- Reverse alphabet secret code

Here’s a simple reverse alphabet code to start with. Write the alphabet on your paper, then write it backwards directly underneath your letters. To write a secret message, use the letters in the second column, i.e. the reverse alphabet. The child will have to reform the sentence by replacing each letter with the one in the top row.

9- Morse Code

The Morse code is an international code that represents the alphabet and allows a message to be transmitted using a series of short or long impulses in the form of written signs but also lights or gestures.

Thus, each sign represents a letter of the alphabet. All you have to do is replace the letter with a Morse code sign to code your text.

Fun ideas for escape game

10- Caesar Cipher

Thus, the code Caesar, comes to us from the famous Roman general, Julius Caesar, who used coded messages to send his orders. He replaced each letter with another, but beware, not  anyhow. It is necessary to follow a precise logic so that the recipient can decipher it properly. Thus, each letter of the message was replaced by the one located 3 rows further in the alphabet. The simplest is then to write the alphabet on one line. And to write a second alphabet on a line below by shifting the letters 3 rands to see the matches. Then you just have to replace each letter by the corresponding one and the message will appear as if by magic.

Of course this code can be adapted; you can shift the letters by the number of rows you want.

11- The backwards sentence

Simply write your sentence starting with the last letter of the word and do the same for the next word and so on, leaving spaces between each word.

To make this type of code even harder, you can also write the sentence starting with the last letter of the whole sentence and work your way back to the first one without spaces. This variant should be adapted according to the age of the children.

12- The mirror sentence

Create an original coded message. Children will need to use a mirror to read the message. This mirror can also be a digging game beforehand: look for the tool that will then be used to decipher the code. To make a mirror sentence, simply write your text on words and use the rotation tool to invert your text.

13- Pigpen Cipher : freemason secret code

Instead of replacing one letter with another, this time we have replaced a letter with a sign.  Thus, the famous “piggy case” code is very appealing to children.

Just draw 4 grids as in the example below. Fill them with the letters of the alphabet. You will notice that each letter is in a well defined box… Depending on the edges and points, these boxes are all different from each other. So, to make a code you will just have to draw the shape of the box and not write the letter.

To decode it, the child will have to understand how the code works and above all to find the letter to which each box corresponds in order to transcribe the message.

Detective mystery game secret code

14- The Dancing Men

This code became known thanks to one of the 46 short stories by Arthur Conan Doyle in the famous Sherlock Holmes series. Thus our detective is also confronted with strange signs.

Each man represents a letter of the alphabet. And each man exists twice: once with a flag and once without a flag. The flag simply indicates that it is the end of a word. So you just have to find out which letter corresponds to each man and translate the message… The men with flags indicate the end of a word and the next man will be the first letter of the next word.

secret code for kids

15- Tap Code

This coded code still comes from the Greeks so as not to change… Just draw a square with 25 squares. Put the letters of the alphabet in it. Attention the C and the K will be placed in the same square. Then place the numbers from 1 to 5 above the first line and to the left of the first column.

To code a letter, simply read these coordinates from the table.

secret code for kids: tap code

16- Letters as drawings as secret code

You can create a table but put drawings or colors instead of numbers… Code your message. With the help of the code, the child will have to find the letter and reconstruct the message. You can vary this style of table infinitely. Just read the coordinates and it’s done.

Print a pirate scavenger hunt for kids aged 8 and older

17- Replace one word with another

You can prepare lists of words in advance where each word will be replaced by another one… So the children will have to find out which real word corresponds to the word used… Make a list from the words of the message you want to code.

Discover all our escape room kits for kids full of puzzles and secret codes to solve.

Escape games for kids

18- A few tips to make your secret code

  • Adapt the message to the age of the children: indeed, the length of the message (and the type of code) will be chosen according to the audience concerned. Messages will not be of the same type or used in the same way for kindergarten children who cannot read, or for elementary or middle school children.
  • Make paper available to children so that they can use it in draft form and make several attempts to decipher the message.
  • Give the children a clue to decipher the coded message.
  • Write the message in uppercase: this writing is readable by everyone, whereas cursive writing is really specific to everyone and can be difficult to read for many children.

Secret codes have been around for centuries… Used during wars, by prisoners, by kings… these codes have always existed and were used to pass messages with the understanding that if they were intercepted then no one could understand them.

These codes have been found and deciphered so that we have had to constantly innovate and invent new ones. With the advent of computers, new codes are still coming to light. So new secret codes will always be used, deciphered and reinvented…

Secret codes are fun for children… All these codes can be used in treasure hunts or police investigations but also in escape game which is a game known for its searches and code resolutions.

This is only a part of the existing codes which are listed here: the most known. We have tried to list all kinds of them, of various styles and different levels.

Discover our website which lists all the game ideas for your birthday parties. Get a lot of great ideas!

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