How to Solve a Cryptogram

The rules in 30 seconds

• Every letter of the message has been swapped for a different letter.
• The same letter is always swapped the same way: if Q is E once, Q is E everywhere.
• Two different letters never share a code letter.
• In our puzzles no letter ever stands for itself.
• Spaces and punctuation are left alone, so word shapes are real clues.

Step by step

1. Use the starter hints. Easy and medium puzzles fill in one or two letters. Mark every one of those letters everywhere it appears and read the partial words.
2. Count the letters. The most frequent code letters are probably E, T, A, O, I or N. The frequency table in the player does the counting for you.
3. Find one-letter words. In everyday English only A and I stand alone, so a lone code letter is almost always A or I.
4. Study the short words. Two- and three-letter words repeat constantly. A three-letter word that appears several times is probably THE or AND.
5. Use apostrophes.A word ending in an apostrophe plus one letter ends in 'S, 'T, 'D or 'M. An apostrophe before two letters is usually 'LL, 'RE or 'VE, and N'T is common.
6. Spot double letters. Doubles are most often LL, EE, SS, OO and TT. A word with a double at the end could be ALL, SEE, TOO or ADD.
7. Match word patterns. Look at which letters repeat inside a word and compare with the table below.
8. Try common endings. -ING, -ED, -ER, -LY, -TION, and common starts such as TH-, WH-, ST-, CH-.
9. Use the self-map rule. If a code letter could be itself, it cannot. That often rules out the first guess you would make.
10. Write lightly and watch for conflicts. If two code letters end up as the same letter, one guess is wrong. Back up, do not bulldoze on.
11. Finish by reading. When about half the letters are in, the rest of the message nearly reads itself.

A worked example

Imagine you are given this coded sentence:

T LII EDI GTU HMU.

1. T is a word on its own, so it is A or I. With a sentence starting that way, try I.
2. LII has a double letter at the end. Words like SEE, TOO and ALL fit that shape.
3. EDI is a three-letter word ending in the same letter as the double word. THE ends in E, and SEE also ends in E, so the pair fits.
4. That makes I = E. The first letters then follow: L = S from SEE, and E = T, D = H from THE.
5. With those letters in, the last two words fall to simple guesses: BIG and DOG.

Plain text: I SEE THE BIG DOG.

Word patterns

A word's pattern shows which letters repeat. Give each new letter the next capital, so LITTLE is ABCCAD (L is A, I is B, T is C, T is C again, L is A again, E is D). A coded word with the same pattern could be any word with that shape.

Practice

Start with easy cryptograms for beginners, move up to medium, and try the daily cryptogram for a new one every day. Prefer paper? See printable cryptograms. Riddle fans can try riddle cryptograms.