Region Logic Puzzles

How it works

A region logic puzzle is a square grid split into coloured or shaped regions, with as many regions as there are rows. You place one piece in every row, every column and every region. In the most common version, no two pieces may touch, not even at a corner. That is the whole rule set, and a well-made puzzle has exactly one answer.

You solve it by ruling squares out. Mark the squares where nothing can go, and the places where a piece must go appear on their own. Small regions are the usual way in, because a region of one or two squares has almost no choice. From there, each piece you place rules out its row, its column, its region and the eight squares around it.

What makes a good one

• One answer, reachable by reasoning alone, with no guessing.
• Regions you can tell apart easily, by shape and texture as well as colour.
• Marks for ruled-out squares, plus undo and redo.
• Hints that explain the next step instead of just filling a square.
• A difficulty curve that teaches new deductions one at a time.

Strategies that help

Start small. The smallest region, or one squeezed into a single row or column, usually gives the first placement.

Count regions against rows. If two regions sit entirely inside the same two rows, those rows are taken. Rule out every other square in them.

Test the squares that block. If a piece on a square would leave a nearby region with no room, that square is out.

Mark everything. After every placement, mark its neighbours, row, column and region straight away.

Our take

Our region logic puzzle is Bloomplot. The grid is a garden, the regions are textured beds inside hedges, and you plant one sprout in every row, column and bed with no two touching. A Gardener’s Notebook explains the next deduction in words, and a Daily Harvest of three plots is the same for everyone. If you like pure grid logic, see nonograms.