How to play Cipher Desk

Cipher Desk is a collection of 250 substitution cryptograms. Each puzzle is a well-known quote and its author, where every letter has been swapped for a different letter. The same swap is used throughout the puzzle, so if X stands for E once, it stands for E everywhere.

• Pick a cell and type the letter you think the blue cipher letter stands for. Every matching cell fills in at once.
• Green letters are given at the start or revealed by a hint.
• Use Hint to reveal a letter, Check to test your guesses, or Clear guesses to start again.
• Arrow keys move between cells, Backspace erases, and Space jumps to the next blank.

Easier puzzles start with some letters already given. Harder puzzles give you fewer letters to start with.

Tips and strategy

• Use the letter counts. The cipher key shows how often each letter appears. In English, the most common letters are E, T, A, O, I, N, S, H, R, D, L, U, so the most frequent cipher letter is very likely E or T.
• Start with short words. One-letter words are almost always A or I. Common three-letter words include THE and AND.
• Look at apostrophes. A letter after an apostrophe is often S or T (IT’S, DON’T).
• Spot repeated patterns. A cipher word with a double letter, like XYYZ, limits the possibilities a lot.
• Use the author. The author’s name is encoded too, and a famous name can unlock several letters at once.

Read the full method in Cracking the Code: Letter Frequency and How to Solve Any Cipher and our Cipher guide.