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Logic Grid Puzzle Generator

The classic form: four people, four drinks, four pets, and a handful of clues that between them pin down exactly who has what. The catalogue could already generate grids of numbers, but nothing where the clues are sentences and the deduction runs through relationships. Every puzzle here is solved exhaustively before you see it, and every clue has been tested by removing it to check a second arrangement does not appear.

What this generator does

Builds a hidden arrangement, derives every clue true of it, then removes clues one at a time and keeps a removal only while exactly one arrangement still satisfies what is left. What you get is a minimal set: take away any single clue and the puzzle becomes ambiguous.

How to use this tool

  1. Choose how many items and categories the puzzle should use.
  2. Read the clues and work out which items go together.
  3. Reveal the answer to check.
  4. Seed it if a group should all get the same puzzle.

Understanding the controls

Items per category
Three or four. Four is the classic size and gives the more satisfying deduction.
How many categories
Three or four. Each extra category adds a whole dimension to work out and roughly doubles the clue count.
Seed
Any word reproduces the same puzzle exactly, which is what makes a shared or printed set possible.
Show the answer
Reveals the arrangement the clues were derived from, laid out as a table.

Common use cases

  • A reasoning exercise that needs no arithmetic at all
  • A printable puzzle for a class or a quiz night
  • Teaching constraint elimination in a form people can do by hand
  • A logic starter that takes minutes rather than an evening
  • Generating a shared puzzle for several people from one seed

How this generator works

The solver enumerates every possible arrangement — one permutation per category after the first — and checks each against all clues. At the offered limits that is at most 13,824 arrangements, which is instant. The limits exist because the count grows factorially, so larger sizes would need a constraint solver rather than enumeration.

Randomness and fairness

The hidden arrangement and the order clues are tested in are random; the puzzle having exactly one answer is not. A seeded puzzle is reproducible and therefore explicitly not cryptographically secure; without a seed the browser's cryptographically secure generator is used.

For how randomness is produced across the whole site, see how Generate Random works.

Limitations and good to know

  • Three scenarios of names and objects, so puzzles repeat their subject matter even though the arrangements differ.
  • Clue types are limited to belongs-with, does-not-belong-with and position. Richer relational clues would need a much larger generator.
  • Sizes stop at four by four because the solver enumerates arrangements and that count grows factorially.
  • Difficulty is not graded — a minimal clue set is not necessarily a gentle one.
  • Puzzles are not stored, so use a seed for anything you want to print or share.

Privacy and your data

Puzzles are generated entirely in your browser. No seed, puzzle or solution is transmitted or kept between visits.

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