The Spartan Scytale

The secret is the stick

The soldiers of Sparta had a clever way to hide a message. They did not swap letters for symbols or numbers. They kept every letter and mixed up the order. The only way to unmix it was to own the right stick.

Work through the menu at the top, one stop at a time.

1. The Story: meet the Spartans and find out what historians still argue about.
2. The Rod: wrap a strip on different rods and watch the words appear.
3. Training: learn to unscramble a strip with no rod at all.
4. Seven Codes: read seven strips from a general who is having a very bad week.
5. Write a Strip: scramble messages of your own.
6. Build Bay: locked until you earn the first five badges. Then you get the plans to build a real scytale.

One more thing. The rod at the very top of this page keeps changing size. At one size, three words appear. Can you catch them?

The city of soldiers

About 2,400 years ago, Sparta was one of the strongest cities in Greece. Spartans were famous for two things: tough soldiers and short answers.

An army far from home needs to get orders. But what if an enemy catches the messenger and reads the message? Sparta needed a way to keep its orders secret.

Two rods, exactly alike

Here is how an ancient writer said it worked. Before a general left for war, the leaders of Sparta cut two wooden rods. The rods were exactly the same length and exactly the same thickness.

One rod stayed home in Sparta. The general took the other one with him. Each rod was called a scytale. Say it like this: SKIT-uh-lee.

Wrap, write, unwrap

To send a message, the leaders wound a long, thin strip of leather around their rod, like the stripe on a candy cane. Then they wrote the message along the rod, across the loops of the strip.

Next they unwrapped it. On the flat strip, the letters were all still there, but they were in a mixed-up order. A spy who grabbed the strip would see nonsense.

When the strip reached the general, he wound it around his own rod. Because his rod was the same thickness, the letters lined up again and he could read the orders. On a rod that was too thick or too thin, the letters would not line up at all.

A different kind of code

Most codes swap each letter for something else. The Caesar cipher swaps a letter for a different letter. The scytale does not swap anything. Every letter stays the same. Only the order changes.

Code makers have a name for this kind of code. They call it a transposition cipher. That is a fancy way to say "a code that moves letters to new positions."

Was it really a secret code?

Here is a mystery. The clearest description of the scytale comes from a writer named Plutarch. He lived about 500 years after the Spartan generals he was writing about.

Older Greek writers mention the scytale too, but they do not say it scrambled anything. So some historians think it may have been a plain message stick, or a way to prove that a message really came from Sparta. Other historians think Plutarch had it right.

Nobody knows for sure. What we do know is that the idea works, and you are about to prove it.

How the rod works

We measure a rod by how many letters fit around it. On a size 2 rod, the strip shows 2 letters each time it goes around. On a size 3 rod, it shows 3.

Below is a strip a messenger just handed you. Use the plus and minus buttons to try thicker and thinner rods. Read each row from left to right, starting with the top row.

On the wrong rod you get nonsense. On the right rod, real words appear. There are no spaces, so you have to spot where each word ends.

Training: deal the strip

What if you know the rod size but you do not have a rod? You can still read the strip. Just deal the letters out like playing cards.

1. Make one row for each letter around the rod. A size 3 rod needs 3 rows.
2. Deal the first letter to row 1, the next to row 2, and so on.
3. After the last row, go back to row 1.
4. When the strip is empty, read the rows from top to bottom.

Deal three strips correctly to earn your badge. If a letter goes to the wrong row, you start over with a new strip.

Seven strips from General Leon

This story is made up, but the code is real. General Leon is far from home with his army. He writes on his rod, unwraps the strip, and a runner carries it back to Sparta. You hold the matching rod.

Read each strip and type the message. Spaces do not matter. Watch out. As the week goes on, you get less and less help.

Write a strip

Now you are the one sending orders. To scramble a message, do what the Spartans did.

1. Write the message along the rod in rows, with no spaces.
2. Now unwrap it. Start at the first loop of the strip and read it from top to bottom.
3. Move to the next loop and read it from top to bottom. Keep going to the end.

Scramble three messages to earn your badge.