Hash
Goal: find an input that produces the output dssoh
Once you have figured out the rule, answer: what input produces "dssoh"?
Tip: Start with single characters (A, 1, x) to isolate the rule. Then probe edge cases · vowels, even-indexed positions, mixed case.
About Hash
Hash is the logic-black-box game · a hidden function transforms inputs into outputs, and your job is to decipher what the function does by feeding it test inputs and watching how the outputs change. The mechanic is the same one programmers use every day when they reverse-engineer an opaque API: you can't see the code, only the behaviour, so you probe with carefully chosen inputs and infer the rule from the pattern.
Three difficulty tiers. Easy ships linear shifts · Caesar cipher (+1 on each letter), simple mirroring, doubling. Medium ships conditional rules · "vowels go to next vowel, consonants stay", "uppercase letters reverse, lowercase don't". Hard ships positional math · the rule depends on the index ("character at even position +1, character at odd position -1"), or arithmetic transformations of the alphabet positions.
The skill is hypothesis-driven testing. The naive strategy is to throw random inputs at the function and look for patterns. The fast strategy is to design inputs that discriminate between hypotheses · if you think the rule might be "+1 letter", test with the input "AAAA": if it returns "BBBB", you have evidence; if it returns "BCDE", you've ruled out the +1 hypothesis and learned the rule is positional. The same epistemic habit shows up in scientific experimentation, debugging, and software-testing strategy.
Budget rewards efficiency. You get up to ten tests per round, but the fewer tests you use to crack the rule the higher you score. After the final guess the round reveals the actual function. Every round is keyed by a seed so the same code reproduces it · useful for shared "can you do it in fewer tests?" challenges.
Part of the PlayMemorize family of brain-training games. Runs entirely in your browser, works offline as a Progressive Web App.
FAQ
Q: How is this different from Wordle?
Wordle hides a single secret word; Hash hides a transformation rule. In Hash you feed the function inputs and read the outputs to deduce what rule it follows · the answer is a function, not a word.
Q: What kinds of rules appear?
Easy uses Caesar shifts (each letter advances by N) and mirroring. Medium adds vowel/consonant-conditional rules (e.g. "vowels advance, consonants don't"). Hard uses positional math · index-conditional rules (the rule depends on whether the position is even or odd, or on the position itself) and arithmetic transformations of the alphabet positions.
Q: How many tests do I get?
Up to ten tests per round. The fewer tests you use to crack the rule, the higher you score. The optimal strategy isn't random sampling · it's designing inputs that discriminate between competing hypotheses. The same skill underpins effective debugging and good experimental design.
Q: Does it work offline?
Yes. PlayMemorize is a Progressive Web App.
