Daily logic puzzle
A fresh logic mystery every day. Read the clues, rule out the impossible, and deduce the one and only solution. Pure logic, never luck, in the spirit of the classic Einstein and Zebra riddles.
Launching on iOS soon
One puzzle a day · Always solvable, no guessing
What it is
DeductaDay is a daily logic-grid deduction puzzle in the spirit of the classic Einstein and Zebra riddles. Each day brings one new case with a handful of natural-language clues. Cross out what cannot be true, lock in what must be, and crack it step by step.
The puzzle is the same for everyone on a given day, and it is always solvable by pure deduction: no guessing, no randomness hiding behind the clues. Difficulty builds through the week, easy on Monday, a real test by Sunday, so the challenge grows without ever becoming unfair.
Tap to rule out a possibility, long-press to confirm a match. There is no way to lose a round outright: a hint or a board reset is always available, so the puzzle stays a puzzle, not a countdown against failure.
Key features
Every part of DeductaDay serves the same goal: a clean deduction, once a day.
The same case for everyone, every day, so a solve time actually means something against friends and strangers alike.
Every case has exactly one solution reachable from the clues alone. No guessing ever improves the odds.
Tap to rule out, long-press to confirm. A hint or a full reset is always there, so the puzzle stays solvable.
Easy on Monday, a real test by Sunday, so the challenge climbs gradually rather than resetting daily.
Build a daily streak and try to beat your own solve time, one case at a time.
Extra puzzles any time the daily case is already solved, plus a spoiler-free way to share a result.
Under the hood
Every daily case is generated so that its clue set uniquely determines one solution: the clues, taken together, rule out every other possibility before a player has to guess. That guarantee is checked before a puzzle ever ships, not discovered by a player halfway through a solve.
The deduction grid tracks ruled-out and confirmed pairs directly, so the same logical steps a player would write on paper are visible on screen: an X for ruled out, a match mark for confirmed, and nothing hidden behind an opaque "check my answer" button.
DeductaDay works fully offline once a day's puzzle has loaded, and the same puzzle is shown to every player that day, which is what makes a solve time and a streak comparable across the whole audience.
Calm by design
Works fully offline
Once the day's puzzle has loaded, no connection is needed to solve it.
Never fatal
There is no way to fail a puzzle outright. A hint or a reset always keeps a solve possible.
Spoiler-free sharing
A result can be shared without giving away the day's solution to anyone who has not solved it yet.
How it looks
Four looks inside a day's case, from first clue to solved streak.
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Status
DeductaDay is launching on iOS soon. Want to hear when it lands? Email contact@mightys.dev.