Mastermind is a code-breaking puzzle. A hidden sequence of colors is generated, and you deduce it within a limited number of guesses using feedback pegs after each try.

What do the green and orange pegs mean?

A green peg means a color is correct and in the right spot. An orange peg means the color is in the code but in the wrong spot. An empty peg means that color is not in the code. Pegs give counts only — they never tell you which slot they refer to.

Does Mastermind allow repeated colors?

The default Solo and Daily Challenge codes use no repeated colors. Duplicates mode allows the same color to appear more than once in the code.

How many guesses do you get?

It depends on difficulty — 10 to 12 guesses. Starter and Classic give 10 guesses for a 4-slot code; Hard gives 12 for a 5-slot code; Expert gives 10 for a tougher 5-slot, 8-color code.

How to Play Mastermind - Rules, Feedback Pegs & Strategy

The basics

How does Mastermind work?

Every game hides a code of 4 or 5 color slots. You submit a guess from the color pool, and the game replies with clues — it never points at a specific slot.

The goal is simple: guess every slot correctly before you run out of turns. The real skill is using each round of feedback to rule out wrong colors, confirm the right ones, and then fix their order.

Mastermind rewards deduction, process of elimination, and a little patience — the same muscles as a good logic puzzle.

Feedback

What do the feedback pegs mean?

Green peg: right color, right spot.
Orange peg: right color, wrong spot.
Empty peg: that color isn't in the code.

Crucially, pegs are counts, not positions. Two green pegs mean two of your colors are exactly right — but not which two. That "total information, not a slot-by-slot hint" is the heart of Mastermind, and what makes each guess a small deduction.

A worked example

One round of reasoning

Open with a spread of different colors to quickly learn which ones exist at all.
Get a green peg? Try to keep that color where it is. Get an orange peg? Keep the color but move it.
Lots of empty pegs? Drop those colors next round and reuse the ones you've confirmed.

A reliable habit: settle which colors are in the code before you fuss over their exact order. Nailing the set first, then the arrangement, usually beats shuffling positions from move one.

Strategy

How do you win in fewer guesses?

Good players treat every guess as a question that splits the remaining possibilities roughly in half. Early on, favor guesses that test many new colors at once — you learn more from a guess that could be wrong in interesting ways than from a "safe" one.

Once you've confirmed the color set, stop introducing new colors and spend your guesses purely on order. And read empty pegs as hard facts: a color ruled out never comes back, so never waste a later guess on it.

Modes

How do the rules change across modes?

Solo and the Daily Challenge use no repeated colors. Duplicates mode lets the same color appear more than once, which removes a shortcut and makes deduction harder. Two-Player lets one person set a code and the other crack it.

For the full breakdown of colors, slots, and guess limits per difficulty, see the modes page.

FAQ

Frequently asked questions

What is Mastermind?

A code-breaking puzzle: deduce a hidden sequence of colors from the feedback you get after each guess.

How is the Daily Challenge different from normal play?

The Daily Challenge gives everyone the same puzzle each day and tracks your daily streak. Normal modes are better for practice, chasing a best score, or playing a friend.

Does sharing my result spoil the answer?

No. A shared result shows only your feedback progress — never the answer colors. A two-player code lives in the link or your local browser.

If the rules make sense, jump straight in — or browse how the modes differ in pace and difficulty first.

Back to the game See the modes About Mastermind online

How to play Mastermind: rules & feedback pegs