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 new cipher every morning, three guesses, and a streak that breaks the moment you miss one. Every past day stays playable in the archive.