How to play Perplexd

LockCode

The rules

• The secret code is four different digits from 0–9 (5,040 possible codes).
• You start with four clues. Each clue is a test code with two counts: ■ digits that are in the code and in the right position, and ● digits that are in the code but in the wrong position. “Nothing” means none of those four digits is in the code.
• The counts never say which digits are right. Two clues that overlap tell you more than either alone.
• You have six guesses. Each guess gets the same two counts.
• The keypad greys out digits that cannot be in the code given everything you know, and a counter shows how many codes are still possible.

Difficulty

The generator keeps the number of codes still possible after the four clues between 8 and 12 — every day. Every puzzle is solvable by reasoning alone; no puzzle needs luck, and your own guesses give you feedback to narrow the field further.

Strategy in four moves

1. Eliminate. A “nothing” clue removes four digits at once. If there is no such clue, two clues sharing three digits with different totals pin down the digit they do not share.
2. Count members before positions. Green plus amber on a clue is how many of its digits are in the code at all. Settle membership across all clues first — most days this leaves the four digits known and only their order open.
3. Probe. When a few arrangements remain, choose a guess whose feedback differs for each of them. It may not be a code that could win, and that is fine: it makes the next guess certain.
4. Place. A digit that was amber in one guess and green in another has told you its column.

A full worked example with the intersection step is on the LockCode page, and every archived puzzle has a deduction walkthrough.

Sharing

One row per guess; green for right-place, yellow for wrong-place, black for misses. The code never appears.

Ladder

The rules

• Three scrambled words: 5, 7 and 9 letters. The 7-letter word uses every letter of the 5-letter word plus two more; the 9-letter word uses every letter of the 7 plus two more.
• Solve the bottom rung to unlock the next. The two new letters at each rung are marked in gold.
• Tap tiles, or type on a keyboard. Tap a filled slot to remove its letter.
• No timer — except the one you choose. Each rung allows twelve tries. Hints reveal the word from the left, one letter at a time, and cost a yellow square in your result. “Give up” reveals the word, marks the rung red, and unlocks the next.
• The Conundrum (optional). When the nine-letter rung unlocks, its letters stay hidden until you choose: 30 s Conundrum starts a Countdown-style clock and reveals the letters; solve it before the clock runs out and your share gets a ⚡ with your time. No clock just shows the letters. Miss the clock and nothing is lost — the rung carries on untimed. Taking a hint ends the clock.

Solving faster

• Look for an ending first: -ING, -TION, -MENT, -NESS, -ABLE, -ATED, -IOUS.
• Keep the word you just solved as a block and find where the two gold letters slot in — you are placing two letters, not nine.
• Pair consonants (TH, ST, PR, ND) and count vowels before arranging.

Sharing

One row per rung: green for letters you placed, yellow for hinted letters, red if you gave the rung up; ✗n counts wrong tries.

Lumen

• A hidden 7×7 pixel picture, against a quiet clock: it starts at your first tap, and a solve shares your time and today’s percentile. Row and column numbers are runs of filled cells in order: 2 2 = two filled, a gap, two filled; 0 = empty line.
• Tap a cell to fill it, again to mark it ✕ (definitely empty), again to clear.
• Six submits. Each submit tells you how many rows and columns are exactly right. Every puzzle has exactly one solution — verified by a solver before publication — so no guessing is ever needed.
• The picture and its name are revealed when you finish, and appear in the archive the next day.

Strategy notes are on the Lumen page.

Streaks, stats and the daily card

• Your streak counts consecutive UTC days on which you finished at least one puzzle. Finishing both is a perfect day. If you played yesterday and not yet today, the home page tells you the streak is at risk.
• When you finish a puzzle you see how you compare with everyone who finished it that day (“you beat 72%”) and a distribution of their results — once at least five people have finished.
• The daily card at the bottom of the home page combines both results into one shareable block with a link to that day’s page.
• Progress and streaks are stored in your browser. Clearing site data resets them; there are no accounts.

Questions

Can I play yesterday’s puzzle?

Yesterday’s answers and walkthroughs are in the archive. Past puzzles are read-only for now.

Why UTC?

One cut-over time for the whole world means everyone is talking about the same puzzle on the same day. The countdown on the page shows your local time to the next one.

Can a LockCode be impossible?

No. Every day’s clue set is checked against all 5,040 codes; the secret code is always among the codes consistent with the clues, and the count is inside the day’s band.

Do Ladder words repeat?

The chain pool is several hundred deep and cycles in a fixed shuffled order, so a 9-letter word returns only after the whole pool has been used.

Further reading

Two longer guides: cracking 4-digit Mastermind codes in four guesses and anagram techniques for long words.

Something is wrong with a puzzle

Email perplexdgame@gmail.com with the puzzle number.