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Suguru Puzzle Generator

Suguru, printed in some papers as Tectonic, cuts the grid into small regions. A region of five squares holds the numbers 1 to 5, once each — and no two equal numbers may touch, not even at a corner. That second rule is what makes it a puzzle rather than five separate ones, because it reaches straight across the region boundaries.

What this generator does

Cuts the grid into regions, fills a valid answer, then takes numbers away one at a time — keeping a removal only while the remaining clues still lead to a single answer.

How to use this tool

  1. Choose a grid size — six by six is the usual newspaper puzzle.
  2. Print or copy the grid; the thick lines are the region boundaries.
  3. Fill each region with 1 up to its size, keeping equal numbers apart.
  4. Show the answer to check, with the filled-in squares picked out.

Understanding the controls

Grid
How large the puzzle is, from five by five up to eight by eight. A larger grid is a longer solve rather than a harder one, since the regions stay the same size.
Seed (optional)
Type anything to rebuild the same puzzle later, which is how you reprint a page you have lost. Deterministic, not cryptographic.

Common use cases

  • A daily number puzzle that needs no arithmetic
  • A puzzle page for a newsletter or a puzzle book
  • Classroom logic practice for pupils who find sudoku a slog
  • A gentler alternative to killer sudoku for a puzzle group
  • Reprinting an exact puzzle later from its seed

How this generator works

Regions are grown to five squares each, which matters more than it looks: every region contains a 1, and no two 1s may touch, so a grid of three-square regions would need a third of its squares to be 1s with none touching — which no arrangement achieves. The answer is then found by a search that always takes the square with fewest possibilities, and clues are removed one at a time, each removal kept only when the puzzle is proved to still have a single answer. The check on the page solves the printed clues again from scratch and compares square by square.

Randomness and fairness

The region cut, the answer and the order clues are removed all come from your browser's cryptographic random source unless you give a seed — deterministic, not cryptographic.

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

Limitations and good to know

  • Regions are at most five squares, which is the standard printed form.
  • Difficulty is not graded; a single answer does not promise the reasoning is gentle.
  • Some region cuts have no valid filling at all and are discarded, so a fresh puzzle takes a moment on the larger grids.
  • A clue is only dropped when uniqueness is proved within a work budget, so a puzzle is occasionally a clue or two easier than it could be.

Privacy and your data

Regions are cut and clues removed entirely in your browser. Nothing you type as a seed, and no puzzle produced from it, leaves the device.