Free games › Codebreaker
🔐 Codebreaker game (Mastermind) — free on Games140
Crack the hidden code. This is classic Mastermind, the 1970s code-breaking game.
- Free to play
- No sign-up to start
- Coaching built in
- Play with friends in groups
How to play Codebreaker
- The computer picks a secret code of coloured pegs. On Standard that is 4 pegs from 6 colours, and colours can repeat — 1,296 possible codes.
- After each guess you are told how many pegs are the right colour in the RIGHT place, and how many are the right colour in the WRONG place. Never which ones — that is where the deduction comes from.
- The count above the board shows how many codes still fit everything you have been told, and ✅ lists what you have already proved.
- After guesses 2 and 4 you are asked what you can conclude with certainty. Exactly one answer is provable from the feedback.
Controls. Pick a level before your first guess. Tap colours to fill the slots, then Guess. Undo removes the last peg.
Scoring
Points for information, not speed: 100 for cracking it in 4 or fewer, 10 less per extra guess. +6 per certain conclusion, +6 for testing one or two pegs at a time, +10 for matching the solver, −4 for any guess that taught you nothing.
Strategy tips
- Change one or two pegs at a time. Change everything at once and you can't tell what the feedback is telling you.
- Watch the count, not the pegs. A good guess is the one that makes it fall fastest.
- New to it? Start on Beginner — no repeats makes the feedback far easier to read.
Levels: Beginner 4 pegs × 5 colours, no repeats · Standard 4 × 6 · Advanced 5 × 7 · Expert 5 × 8 in 8 guesses. Three well-played games in a row moves you up.
What it trains
Codebreaker is part of the Reasoning (deduction) group of games on Games140. Games140 is a set of free daily thinking games with coaching: you can play first and sign up later to save your streak, keep your level, or join a group with friends or family.