Summary: A Codeword — also called a cipher crossword — is a crossword with no clues at all. Every white square holds a number from 1 to 26, the same number always stands for the same letter, and a few letters are printed to start you off. This guide covers the rules, the key strip under the board, and a worked example of cracking your first number.
Overview
Start with an ordinary filled crossword — every white square holding a letter, every letter part of a word going across and a word going down. Now throw the clues away and replace each letter with a number: every A becomes the same number, every B becomes a different one, right through to Z. Print a few of those letters back onto the board as a head start, add a key of twenty-six numbered boxes underneath, and you have a Codeword.
The same puzzle twice: as it prints, and solved. No clues, no dictionary — the numbers and the key are the whole puzzle.
There are no clues to answer and nothing to look up — an entry you have never met still arrives letter by letter from its crossings. You are breaking a code, and the crossword underneath is what tests each guess.
The Goal
Work out which letter each number from 1 to 26 stands for, then write every letter into its squares so the whole grid reads as a finished crossword. Fill the key in as you go; when the last box is written, the grid is finished.
Codeword Puzzle Rules
- One number, one letter, every time. The cipher is a straight swap: each letter of the alphabet gets its own number, no two letters share a number, and the pairing holds for the whole puzzle. Find that 8 is E once and every 8 on the page is an E.
- The finished grid is a real crossword. Every white square is part of a word reading across and a word reading down, the shortest entry is three letters, the white squares all join up into one region, and no word appears twice. That double-checking is what lets you test a guess: a letter you try in one direction has to make sense in the other.
- Every square sits in two entries, so you rarely have to recognise a word to finish it. The entries are ordinary English, and a crossword this dense will occasionally reach for a less familiar one — which matters far less here than in a clued crossword. Because each square is shared with a crossing word, an entry you have never seen usually fills itself in from letters you established elsewhere. You read it after you have written it.
- The scarce letters are often not on the board at all. Many grids use no J, Q, X or Z, and those are simply handed to you in the key. Where one is used, it usually turns up in an everyday entry — JAZZ, QUIZ, ZEBRA, LYNX and the like — and if it is a word you do not know, the crossings still spell it out for you.
- Starter letters are given by letter, not by square. When a puzzle hands you H as a starter, every H on the board is already printed, and the key box for that number is filled in too. How many squares that lights up depends on how often the letter appears: in the puzzle above, three starters print five squares.
- Letters the grid never used are handed to you. The key under the board accounts for any missing letter. If the crossword uses no X, the X is already sitting in its box in the key, because its number appears nowhere on the board for you to work from.
- The black squares are symmetrical. The pattern reads the same rotated a half-turn, the same build standard a newspaper crossword uses. A hand-drawn grid is held to the same rule, and may only differ in being an even size.
The Key Under the Board
Under every Codeword sits a strip of twenty-six numbered boxes, two rows of thirteen. It is your working space and your progress bar: you write each letter into its box as you establish it, and the empty boxes are what is left to find.
Eight boxes are filled before you start, from only three starter letters — the other five are letters this grid never used.
That gap is worth understanding, because it is free information. Two kinds of box arrive pre-filled: your starter letters, and every letter the crossword did not use. You can tell them apart in a second — a starter letter’s number also appears on the board, an unused letter’s number appears nowhere. Both are gifts, but only the starters help you place squares.
How to Solve a Codeword, Step by Step
Steps 1 and 2 are worked on the bottom-right corner of the puzzle at the top of this page, shown here on its own.
The three starter letters stack in one column. The square below them is the deduction.
- Spread the starter letters first. Write each given letter into every square carrying its number, right across the board. It is free progress, and it costs nothing but a minute. Where those squares land is luck: sometimes they scatter, and sometimes — as in the puzzle above, where all five sit in the bottom-right corner — they cluster, which is its own kind of gift.
- Look for a part-filled entry with only one gap. This is where a Codeword cracks open. In the puzzle above, the three starters stack in a single column — H, Y, P reading downwards, with one more square beneath them numbered 8. Two words fit: HYPE and HYPO. Now count that number across the board — 8 is on twenty-four of this grid’s hundred and thirty white squares, far and away the most common. A letter that frequent is E long before it is O, so pencil in HYPE and check the words it lands in. They hold. One deduction, nearly one square in five.
- Count the numbers you cannot place yet. The most frequent number on a board is almost always E. After that, expect A, R, S, T, O and N in some order — treat that as a shortlist to test, not a ranking to trust. A high count on a number you have not identified is a strong candidate for a common letter, and you can try it in a short entry before committing.
- Cross-check before you commit. Every letter you write sits in two words at once. Try it in the crossing word before you accept it — if the crossing turns into nonsense, try a different letter for that number, and you have narrowed the field for free.
- Work the endings and the doubles. A repeated number at the end of several words is usually E or S. A doubled pair inside a word is usually LL, EE, SS or OO. A three-letter entry ending in the number you have pencilled in as S is very often a plural, which confirms both letters at once.
- Close from the key, not the board. Late on, stop reading the grid and read the strip: the boxes still blank are the letters still unplaced, and you match those against the shape of the gaps. The ones that hold out longest are the letters with only a square or two on the board — a K, a W, a B. The genuinely scarce letters are usually already sitting in the key, handed to you because the grid never used them.
Easy and Regular
The same puzzle comes in two moods, and the difference is how quickly the grid opens up.
Left: Easy, six starter letters and a fuller key. Right: Regular, three. Same grid size, different amount of free progress.
Both settings fill from the same pool of everyday English — neither one reaches for harder words. Easy prints six starter letters, so more squares are filled before you start and more of the key is already written in. Regular prints three, and on the bigger boards it builds on a more open grid with longer entries, so you work the key longer before it opens up. A Regular puzzle is a longer solve, not an obscurer one.
Try It Online
A Codeword plays well in a browser because the cipher does the bookkeeping for you: click any square you still have to fill — or any empty box in the key — and type a letter, and it drops into every square sharing that number at once, with the key box filled in to match. Backspace clears the letter everywhere, so a wrong guess costs one keystroke to undo, and Esc lets go of the square. For the general controls — checking your answer, resetting, the timer, and working through a set — see How to Play Puzzles Online.
Outcome
You now know what a Codeword asks of you — crack a 1-to-26 cipher, not recall a definition — and how it cracks: spread the starters, find the entry with one gap, let a single deduction cascade across every square carrying that number, and close the last few letters from the key rather than the board. Want to make your own? See How to Create Codeword Puzzles in Puzzle Maker Pro, or try the free demo first.
FAQ
Do I need to know any unusual words?
No. You are decoding numbers, not answering clues, so a word you do not recognise still fills in from its crossings — you only read it once it is written. The entries come from a common-word pool, so most of the grid is familiar anyway.
Is a Codeword the same as a cryptogram?
No. A cryptogram enciphers a sentence, and you have only that sentence to work from. A Codeword enciphers a whole crossword grid, so every letter sits in two entries at once, which is what lets you crack it without any clues.
What is the difference between a Codeword and a crossword?
A crossword gives you clues and asks you to know the answers. A Codeword gives you no clues at all: the answers are already in the grid, disguised as numbers, and your job is to work out the cipher.
Why are more boxes filled in on the key than I was given starter letters?
Because any letter the crossword did not use is filled in too — its number never appears on the board, so it is printed for you instead. A starter letter’s number also shows up in the grid; an unused letter’s does not.
Does every Codeword use all 26 letters?
Not always, and it does not need to. A smaller grid in particular will skip several letters. Whatever the grid leaves out is already showing in the key, so the strip always ends up complete.
Where do I start if nothing looks obvious?
Write your starter letters into every square that carries their numbers, then hunt for an entry that is one square short of complete. Failing that, count which unidentified number appears most often and test it as E.