Kid Who Did presents

Secret Agent Training!

Crack the code before the grown-ups do.

Give your kid a screen-free adventure they get to lead.

30 printable spy missions for ages 8 to 12: crack secret codes, reveal invisible messages, and build a mission for the whole family.

Kids get the thrill of being a spy. Along the way, 10 missions also help them practice spotting fake links, protecting personal information, and understanding stronger passwords.

Watch three more missions

Every mission is a lesson page and a play sheet. Some are solo puzzles; others need a partner or a grown-up.

Mission 11

Crayon Invisible Ink

Write in white crayon, then paint to make it appear.

The paper: a blank message card

You'll need: a white crayon, watercolors, a brush

The Mission 11 lesson page in the book: Crayon Invisible Ink.

The page in the book. Tap it to look closer.

What it looks like at your house

A note turns up in your lunch bag: GDG DWH WKH ODVW FRRNLH. You'll need your kid's code wheel to read it.

Saturday's treasure hunt runs on clues your kid wrote in code, and you're the one stuck on clue three.

A text says you won a gift card. Your kid compares the link with the real address and says, "That doesn't match. Look at the m."

Spy skills, with house rules

A spy book could teach sneaky habits. This one opens with the Agent Rules on page 5, and every mission follows them.

  1. Codes are for games and surprises. Your agent can always show them to a safe grown-up.
  2. Spy on puzzles and games, never on people.
  3. Ask before you dust anything for prints.
  4. Online, use your codename. Your real name, school and address stay private.
  5. If something online feels like a trick, show a grown-up.

30 missions, from a first code to a mission for the whole family

marks the missions that also teach an online safety skill.

Level 1

Secret Messages

Write your first notes in code.

  1. 1Agent ID
  2. 2Mirror Message
  3. 3Number Code
  4. 4The Pigpen Code
  5. 5The Shift

Level 2

Codebreaking

Crack codes and build stronger ones.

  1. 6Try Every Key
  2. 7Count the Letters
  3. 8Crack It With E
  4. 9The Keyword Code
  5. 10Code Race

Level 3

Hidden in Plain Sight

Hide messages where people don't look.

  1. 11Crayon Invisible Ink
  2. 12The Hole Card
  3. 13Wrap It on a Pencil
  4. 14The Grocery List
  5. 15The Dead Drop

Level 4

Spy Skills

Train your eyes and your memory.

  1. 16The Memory Tray
  2. 17Fingerprint Lift
  3. 18The Quick Disguise
  4. 19What Changed?
  5. 20The Tap Code

Level 5

Cyber Agent

Catch the tricks that fool grown-ups online.

  1. 21Look-Alike Letters
  2. 22The Trickster's Tells
  3. 23Photo Detective
  4. 24Roll a Password
  5. 25Who's Really Calling?

Level 6

The Final Mission

Build a mission for your family to crack.

  1. 26The One-Time Pad
  2. 27Plan the Mission
  3. 28Write the Clues
  4. 29The Big Mission
  5. 30Agent Graduation

Open it to any page

Black and white, US Letter, made to print at home. Tap a page to see it up close.

The cover: Kid Who Did presents Secret Agent Training! 30 spy missions, with a code wheel and an agent holding a magnifying glass.
The cover
Your Training: six levels of five missions each, with a box to check off every mission.
Your training map
Mission 5 lesson page, The Shift: four pictures show how to cut out the wheel, set key 3, and write and read a secret.
Mission 5: the lesson
Mission 5 play sheet: three coded notes to crack with the wheel, the first one done, then a box to write a secret of your own.
Mission 5: the play sheet
Mission 21 play sheet, Look-Alike Letters: six pairs of web addresses, one real and one fake in each pair.
Mission 21: spot the fakes
Mission 23 play sheet, Photo Detective: a kid's photo of their new house with five clues to find, and a table for what each clue tells a stranger.
Mission 23: photo clues
Mission 11 lesson page, Crayon Invisible Ink: write in white crayon, then paint over it to make the message appear.
Mission 11: invisible ink
The graduation certificate: Certified Secret Agent, with a seal, a box for the agent's thumbprint and a line for the Head of the Agency.
The certificate
The code wheel page: a big wheel of real letters and a small wheel of code letters, with dotted lines to cut along.

The paper does part of the work

Mission 5's code wheel is a page in the book. Print it and cut out the two circles. A grown-up pokes a small hole in each center, and a paper fastener joins them. Your kid now has the same wheel as the one at the top of this page.

Other missions come with their own tools to cut out: a hole card that finds words hidden in a page of letters, strips to wind around a pencil, signal cards for a dead drop and a dice word list for building practice passwords.

Tip from the book: glue the wheel page to a cereal box first, and the wheel lasts.

To: Grown-ups

From: Kid Who Did

Re: What the missions are really teaching

Kids pick this book for the spy stuff. Along the way, 10 of the missions connect spy skills to online-safety habits, and each one has a note to help you talk about it.

  • Mission 1: Agent IDCodenames are a real privacy habit. For games and apps, help your agent pick a username that doesn't show their real name, birthday or school.
  • Mission 5: The ShiftThis is the Caesar cipher, the great-great-grandparent of the encryption in your phone. It has only 25 keys that change the letters, so it is easy to crack (Mission 6 tries them one by one). Strong modern encryption uses keys with so many possibilities that trying them all is not practical, which is also why a long, hard-to-predict password beats a short one.
  • Mission 6: Try Every KeyWhen a code has only a few keys, you can try them all. Attackers guess passwords the same way, so short, predictable ones fall first. Many devices and websites also slow down or block repeated guesses.
  • Mission 9: The Keyword CodeA keyword mixes up the alphabet in far more ways than a shift, but letter patterns can still crack it (Mission 8 shows how). Real passwords need to be long, unique and hard to predict.
  • Mission 17: Fingerprint LiftSome phones unlock by comparing the tiny details of a fingerprint with a saved pattern. The loop, whorl or arch shape alone is not enough to unlock a phone.
  • Mission 21: Look-Alike LettersComparing an address with one you already trust, letter by letter, can show a look-alike (rn for m, 1 for l). If a link seems odd, stop and show a grown-up, and go to websites you already know.
  • Mission 22: The Trickster's TellsThe same warning signs show up in phishing emails, scam texts and game-chat scams.
  • Mission 23: Photo DetectiveKeep details that point to your home or school out of public posts, like house numbers, street signs and school names. Don't use a pet's name as a password, and choose security-question answers other people can't find out.
  • Mission 24: Roll a PasswordRandom words picked with dice make passwords that beat clever swaps like p@ssw0rd, but this short list is for practice only. For real accounts, help your agent use a password manager, or roll six or more words from a big list like the EFF's, with a different password for every account.
  • Mission 25: Who's Really Calling?Agree on a private family password. If a call sounds urgent or strange, hang up and call the person back on a number you already know. Practice with a pretend password, and choose the real one privately.

What you get for $27

  • The printable book: 30 missions, each with a lesson page and a play sheet.
  • The cut-outs: the code wheel, the hole card, pencil strips, signal cards and the dice word list.
  • The Agent Rules, a guide for grown-ups and a graduation certificate.
  • Permission to print it as often as you need, for your home, your class or your group.

$27

One payment. Instant download.

Get the book for $27

The 30-Day Mission Guarantee

If your agent hasn't cracked a code they're proud of within 30 days of buying, reply to your receipt email and we'll refund your $27. We'll take your word for it, and you keep the book.

Questions before you buy

What ages is it for?

8 to 12. The first missions are quick wins an 8-year-old can do alone, like making an agent ID card. The later levels build to a full mission for the family, which older kids love. Younger kids can join in with a grown-up.

What do we need?

A printer, pencils and scissors. A few missions use things from around the house, like a white crayon and watercolors, cocoa powder and a metal spoon, a paper fastener for the code wheel, or a die. Each mission lists what it needs at the top of the page.

Will it teach my kid to keep secrets from me?

No. The first Agent Rule is that codes are for games and surprises, and kids can always show their codes to a safe grown-up. If anyone asks them to keep a secret that worries them, they tell a safe grown-up. Several missions also need a grown-up to play the other side.

Does any of it happen online?

No. The online-safety missions use printed examples, so kids practice spotting fake links and photo clues on paper first.

Is it a printed book?

It's a PDF you download right after checkout. Print it at home or at a print shop, and print a page again whenever you need a fresh copy.

Can I use it with my class?

Yes. A teacher or group leader who buys it can print copies for their own class or group. Please don't share the file itself.

What if my kid doesn't like it?

If your agent hasn't cracked a code they're proud of within 30 days of buying, reply to your receipt email and we'll refund your $27. We'll take your word for it.

Mission briefing over

Mission 1 takes a few minutes: pick a codename and make an agent ID card. The rest of the training is in the book.

Get the book for $27
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Terms

Last updated November 2, 2026

These terms cover buying and using Secret Agent Training!, a printable activity book from Kid Who Did, sold as a download. "We" and "us" mean Kid Who Did. "You" means the person who buys it. Buying the book means you agree to these terms.

What you're buying

A PDF of 30 missions, sized for US Letter paper, that you download after checkout. Nothing is shipped. The price is in US dollars and you pay it once: there's no subscription and nothing renews.

Printing and sharing

The book's pages, drawings and words remain ours.

Supplies and supervision

Some missions use scissors, paint, cocoa powder or a partner. Each mission lists what it needs at the top of its page, and the Agent Rules come first in the book. You decide which missions suit your child and your household, and you're responsible for supervising them.

The 30-Day Mission Guarantee

If your kid hasn't cracked a code they're proud of within 30 days of buying, reply to your receipt email and we'll refund your $27. We'll take your word for it, and you don't need to send anything back.

Paying and getting the book

Checkout and payment are handled by our payment provider, so your card details go to them, not to us. After you pay, you get your download link on the confirmation page and in your receipt email. If the link doesn't work, reply to that email and we'll send a new one.

Kids

You need to be 18 or older to buy the book. Kids use it with your say-so and your supervision.

What the book is, and isn't

Secret Agent Training! is for fun and for learning. Its online-safety missions teach habits; they aren't a guarantee against scams or a substitute for your own supervision online. The book is provided as it is. To the extent the law allows, our responsibility to you is limited to what you paid for the book.

Changes

We may update these terms, and the date at the top shows the latest version. The terms in place when you bought still cover your purchase.

The law that applies

These terms are governed by the laws of the State of Arizona, USA. Nothing in these terms limits consumer rights that can't legally be excluded where you live.

Questions

Reply to your receipt email and we'll get back to you.
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Privacy

Last updated November 11, 2026

This policy covers Secret Agent Training! and this page, from Kid Who Did ("we" and "us"). The short version: we collect what we need to sell you the book and help you with it, and this page uses two tools, from Meta and Microsoft, that show us how our ads and the page are working. We don't sell or rent our customer list.

What we collect

The two tools on this page

You can block or delete cookies in your browser's settings. The page works without them.

How we use it

Who we share it with

Only the services that help us do the jobs above: our payment provider, our email service, the company that hosts this page and your download, Google, which serves this page's fonts, and Meta and Microsoft through the two tools. Our customer list isn't for sale or rent.

Kids

This page and the checkout are for adults. We don't knowingly collect personal information from children under 13, and the book itself is a printable PDF that collects nothing. If you think a child has sent us information, reply to your receipt email and we'll delete it.

How long we keep it

Purchase records stay as long as tax and accounting rules require. Emails stay until your question is settled, or until you ask us to delete them. Meta and Microsoft keep what their tools collect under their own policies.

Your choices

You can ask to see, correct or delete the information we hold about you by replying to your receipt email. Depending on where you live (California or the European Union, for example), you may have more rights, and we'll honor them.

Keeping it safe

Payments go through a provider that meets the card industry's security standard (PCI DSS). The rest of what we hold sits in accounts protected by passwords and two-step sign-in.

Changes

If we change this policy, we'll update the date at the top.