🎬 Watch first: Caesar explains the cipher wheel

Press play to hear Julius Caesar explain his secret code.

TOP SECRET · CODEBREAKER TRAINING

Julius Caesar's Secret

About 2,000 years ago, the Roman general Julius Caesar sent secret messages to his army. His trick was simple: he moved every letter in the message forward a few steps in the alphabet. If the shift was 3, then A became D, B became E, and C became F.

Only someone who knew the secret shift could read it. Your job is different. Nobody will tell you the secret shift. You'll use a cipher wheel to turn the letters back, and you'll have to figure out the right turn by testing.

🎡 How the wheel works

IThe outer ring (gold) has the letters of the CODED message.
IIThe inner ring (teal) has the REAL letters. It turns like a dial.
IIITurn the inner ring. Each coded letter on the outside lines up with a real letter on the inside.
IVFind the turn where the message turns into real words, then type it!
🕹️ Turn the wheel any way you like: drag it with your finger or mouse, tap the ◀ ▶ buttons, or press the ← → arrow keys on your keyboard.

🧪 Practice wheel

Try it first! Turn this wheel, then type a word. It shows you what your word becomes when it's coded with the wheel's current turn.

Coded with this wheel setting:

…
🔑 To CODE a letter, find it on the inner (teal) ring and read the gold letter next to it. To DECODE, do the opposite: start on the gold ring.

💡 Detective tips

🔤 A one-letter word is almost always A or I.
🔎 Watch for common words like THE, YOU, and IS.
🔁 There are only 25 possible turns. If one doesn't work, try the next!
👆 Tap a coded letter to see what it becomes at your current turn.

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