Logic & planning game · Grades 1–13
Code Cracker: Free Logic Game for Kids
Code Cracker is a free logic game in the Mastermind family. Guess the secret colour code, read the clues and use them to narrow it down. Crack the vault before you run out of guesses.
Part of our 24 brain games for kids, free with an account.
What Code Cracker trains
Code Cracker practises deductive reasoning (combining several clues to reach a conclusion that must be true), hypothesis testing (choosing a guess that tells you something new, not just a lucky try) and working memory (holding earlier clues in mind while planning the next guess).
What the research says: Using each clue to rule out options is deductive reasoning, and remembering earlier guesses adds working memory; both rely on executive functions that improve with practice (Diamond & Lee, 2011).
Who Code Cracker is for
Code Cracker suits Grades 1–13. The Starter level marks each peg directly, so young players can link a clue to one position. Later levels give only counts, which asks players to reason about the whole row. The clue checker gently flags guesses that contradict earlier clues. Every colour also has its own shape, so colour-blind players can play every level.
How to play Code Cracker
- Choose a level.
- Make a guess by filling the row with colours.
- Read the clues: which colours are right, and which are in the right place.
- Use the clues to rule codes in or out, then guess again.
- Crack the code in as few guesses as you can.
Tips for parents and teachers
Ask “What did that clue tell you?” after each guess, before the next one. Try Two players: one sets the code, one cracks it, then swap; fewest guesses in total wins. One or two codes a day, spread over weeks, beats a long sitting. Fun fact for older students: Donald Knuth showed in 1977 that any 4-peg, 6-colour code can be cracked in five guesses or fewer.
FAQs
What age is Code Cracker for?
Grades 1–13, roughly ages 6 to 18. Starter gives a clue for each peg; harder levels give only counts, which challenges teenagers and adults.
Is Code Cracker like Mastermind?
Yes. It is a deduction game in the same family: guess a hidden code and use feedback to work it out.
Can two people play?
Yes. In Two players mode, one person sets the code and the other cracks it, then you swap.
Is Code Cracker colour-blind friendly?
Yes. Every colour has its own shape, so it can be played without telling colours apart.