Caesar

Named after Julius Caesar, who reportedly used it to protect military messages, the Caesar cipher is the simplest and most recognizable encryption method you'll encounter in escape rooms. Once you know the trick, you can decode it quickly.

What It Is

A Caesar cipher replaces each letter with another letter a fixed number of positions down (or up) the alphabet. With a shift of 3, A becomes D, B becomes E, C becomes F, and so on. The alphabet wraps around, so X becomes A, Y becomes B, Z becomes C. The most famous variant is ROT-13, which shifts by 13 positions — convenient because applying it twice returns you to the original text.

How to Solve It

1. Recognize it. If you see text that looks like English words but all the letters are wrong, suspect a Caesar cipher. Look for short words — a single-letter word is almost certainly A or I.
2. Find the shift value. Rooms often provide the shift number as a clue. Look for a number between 1 and 25 associated with the encoded message.
3. If no shift is given, try frequency analysis. The most common letter in the cipher text likely corresponds to E (the most frequent English letter). Count the letters to find your shift.
4. Decode manually. Write the alphabet on paper, then write a second alphabet below it shifted by the key number. Use this as your lookup table.
5. Check your work. If the decoded text makes sense as English, you've found the right shift. If not, try shifting by 1 more or less.

Examples

The Emperor's Note: A scroll reads "PHHW DW QRRQ." A bust of Caesar nearby has the Roman numeral III (3) on its base. Shifting each letter back by 3: P->M, H->E, H->E, W->T... The message reads "MEET AT NOON."

The Alphabet Wheel: Two concentric discs with the alphabet are pinned to a board. Rotating the inner disc aligns each cipher letter with its plaintext equivalent. A message on the wall decodes to a four-letter word for a word lock.

ROT-13 Riddle: A computer screen shows "GUR PBQR VF FRIRA." Applying ROT-13 (shift 13): G->T, U->H, R->E... It reads "THE CODE IS SEVEN."

Difficulty Variations

Easy: The shift value is clearly provided (e.g., a number written next to the message), and the encoded text is short — just a word or two.

Hard: The shift value must be deduced from another puzzle, or the cipher uses a non-standard alphabet (numbers mixed with letters). Some rooms combine Caesar shifts with other encoding methods for a layered cipher.

Related Puzzles

The Caesar cipher is one of several substitution ciphers you might encounter. The Pigpen cipher replaces letters with geometric shapes instead of shifted letters. Morse code is another common encoding system, though it transforms letters into signals rather than other letters.