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Mind Cipher

Guess the code. One report is lying.

A Mastermind-style code-breaking puzzle for iPhone, filed as a spy dossier. Every analysis comes back as a row of ink marks — and in the Lie file, exactly one report is fake.

Get it on the App Store See a case ↓

Free to start · $2.99 unlocks everything · No ads · No account

Lie file · sample report 4 pegs · 6 colors

  1. I
  2. II
  3. III

Rows I and II use the same four colors. Row I says none of them are in the code; row II says all four are. Both cannot be true — one of these reports is fake.

A Lie case, opened to closed.

  1. 1

    Place your pegs.

    Pick colors into the slots and submit the analysis. Cases run from 4 pegs and 6 colors up to longer codes with 8.

    Your next analysis

    Palette

    Slots

  2. 2

    Read the marks.

    Each submitted row comes back with four ink marks. The marks never say which peg they refer to. That gap is the puzzle.

    right color, right slot right color, wrong slot not in the code at all

    What comes back

    Analysis

    Report

    Two of these four colors are in the code — if this report is honest. In a Lie case you still have to prove that.

  3. 3

    Spot the fake.

    One row in every Lie case is fake, so a clean deduction can still walk you into a wall. Find the two rows that cannot both be true, throw the bad one out, and rebuild from what is left.

    A pair that cannot both be true

    Row I

    Row II

    Row I says none of these colors are in the code. Row II says all four are. One of those reports is fake.

A Mind Cipher case in progress: Challenge No. 0908 on cream paper, two analyzed rows of numbered color seals with dot, ring and dash marks beside each, an evidence tray and the color palette below.

Classic cases

240 cases from beginner to master, each a numbered sheet in the file. The attempt counter sits top-right; the marks are pure ink — dot, ring, dash — so they never depend on color.

  • Every past analysis stays on the sheet for cross-referencing.
  • Notes on the board mark eliminated and confirmed colors.
  • A Shape Marks setting gives every color its own outline.
  • First 40 cases are free.
A Lie case in Mind Cipher: the same board with a red stamp warning that one report in this case is fake.

Lie cases

A separate 240-case file. Same boards, one faked report per case, and a red stamp that reminds you not to trust the page.

  • Only one row per case is faked — never two.
  • Attempt budgets are looser here, because you will burn analyses proving a lie.
  • First 80 cases are free.
Today's Case in Mind Cipher: a streak ledger, a calendar with closed days stamped, and today's puzzle settings.

Today's Case

One puzzle a day, identical for everybody. The settings are published before you start — code length, color count, attempt budget, whether repeats are allowed. Top Secret days are lie cases.

  • Streak and total are kept in a ledger on the device.
  • Closed days stay stamped on the calendar; a home-screen widget shows today's status.
  • Free, always.

Everything in the file.

Mode What it is Access
Today's Case One shared puzzle per day, with a streak ledger and a widget. Free
Classic cases 240 cases, beginner to master, honest marks. 40 free
Lie cases 240 cases where one report per case is fake. 80 free
Duel Mode Pass one phone back and forth. One sets a code, one cracks it. Free
Challenge a friend Send a case you closed as a link. They get the same code. Free
Free Play Endless generated boards at any difficulty you set. Pro
Custom Level Build your own board — length, colors, attempts, repeats. Pro

Pro is $2.99 once. It opens the remaining 360 cases, Free Play and the editor. No subscription, no ads, no account, and progress never leaves the device. Two themes — Dossier and Night Desk — and the app follows your language or the one you set in Settings.