What is Mastermind Deduce?

A free code-breaking deduction game. Each round shows a history of past guesses and their black/white peg feedback. Exactly one candidate code is consistent with every row · pick it to build a streak. Miss once and the run ends.

How is the answer validated?

A pure function called verifyFinalDeduction replays the entire history against the full no-repeat permutation space (6 colours, 4 pegs, no duplicates · 6P4 = 360 codes). If your chosen code is the unique survivor · the only code consistent with every row of feedback · the answer is correct.

What do the black and white pegs mean?

Standard Mastermind rules. A black peg means a peg in your guess is the right colour and the right position. A white peg means a peg is the right colour but the wrong position. The order of the pegs in the feedback does not map to the positions of the guess.

Is every round solvable by pure deduction?

Yes · the generator only keeps history rows that actually prune the candidate space, so the puzzle always narrows to exactly one survivor. No guessing required.

How does my progress save?

Your high streak is stored locally in your browser.

Mastermind Deduce · 日本語

過去の推測とペグフィードバックから秘密のコードを解読しましょう。純粋な演繹的推論、ズル耐性のある検証。JavaScript が必要です。

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Mastermind 推理