Every cipher that turns up in the daily puzzle, explained: how to spot it, what its key looks like, and a worked example you can follow letter by letter. They run in the same order the daily cipher teaches them — one family a week, easiest member first.
A substitution cipher swaps every letter for another letter and keeps that swap for the whole message. The text still looks like text — same word lengths, same spacing, same doubled letters — it just isn't in English yet.
A symbol cipher replaces each letter with a mark — a shape, a pattern of dots, a pair of flags. Nothing is scrambled and nothing is shifted, so once you have the key you can read the message straight off.
A transposition cipher doesn't change any letters at all. Every letter of the answer is already in front of you; they have simply been written down in the wrong order.
A polyalphabetic cipher is a shift cipher whose shift keeps moving. A key word steps along under the message, and each letter is shifted by whichever key letter happens to be beneath it.
These are the ciphers that actually turn up inside treasure hunts, where the encoding is one layer of a puzzle rather than the whole puzzle. They tend to hide the message rather than merely scramble it.
A grid cipher lays the alphabet out in a square — usually 5×5, with I and J sharing a cell — and describes each letter by where it sits. Some stop there; others shuffle those coordinates or push pairs of letters through the square together.
These aren't really secret. They're the ways machines and devices spell — binary, hex, Base64, phone keypads, keyboards, and the Enigma machine — and they turn up in puzzle hunts because they look impenetrable until you know the trick.
No key is given. Detective days hand you the ciphertext and nothing else, so the work is finding the key — or proving which cipher it is — before you can read a word of it.
A new cipher every morning, three guesses, and a streak that breaks the moment you miss one. Every past day stays playable in the archive.