Free logic puzzle — instant play, no signup, no download
Safe Cracker gives you a combination to deduce from feedback. Each attempt tells you how close you are, and the skill is in choosing attempts that maximise what you learn rather than attempts that feel likely. It is the same deduction structure as Codebreaker in a different costume.
A secret combination is generated.
Enter an attempt.
Feedback tells you how close each digit is.
Use the feedback to eliminate possibilities.
Crack it before your attempts run out.
Deduction from partial feedback, and the discipline of choosing informative guesses over plausible ones. The best first guess is rarely the most likely combination.
Open with distinct digits to maximise information from the first attempt.
Change one position at a time when you are close, so feedback is unambiguous.
Record eliminated digits. Re-testing a ruled-out digit is the commonest wasted attempt.
A 'nothing correct' result is the most valuable feedback there is — it rules out every digit you used.
Only on the first attempt. After that it is pure deduction.
The same logic with a safe-dial presentation. Codebreaker offers difficulty modes including unique-digit play.
Distinct digits spread across the range. Repeats tell you less.
Almost always because of a guess that was not informative — one that could not rule much out regardless of the answer.