The Caesar cipher, or shift cipher, is one of the simplest encryption puzzles. It is a substitution cipher where each letter in the original message is replaced with a letter corresponding to a certain number of letters ahead or behind in the alphabet.
For example: "Go right" could be shifted up 1 letter to "Hp sjhiu".
Another: "The key can be found under the old oak tree" shifted 1 up would be "Uif lfz dbo cf gpvoe voefs uif pme pbl usff"
This easy Caesar Cypher tool by Robert Eisele is great to create your own puzzles.
Sometimes the players will have no idea what to do; here are a few tips to point them in the right direction without breaking immersion:
- Don't make solving the puzzle critical to moving forward. It is crucial that they be allowed to fail if they can't figure it out
- Can they find a half-finished solution somewhere? Maybe the cypher was decoded by the enemy they just killed and half of the note is burned or covered in blood making it only partially readable - prepare this as a prop beforehand to really impress your players
- If they fail the first time, let it come up again later - this will build up the excitement for when they finally figure it out and make you look like a fuckin' genius rather than a failure
Have you ever used a cypher puzzle in your game? How did it turn out? Share your story in the comments below!