Heyawake is a shading puzzle from Japan. For every square, you decide if it is shaded or white. The rooms, the numbers and a rule about long white lines tell you which.
The rules
- Thick lines split the grid into rooms.
- A number in a room tells you how many of its squares are shaded.
- A room without a number can have any number of shaded squares.
- Shaded squares never touch side by side. They may touch at the corners.
- All white squares must stay joined along their sides.
- A straight line of white squares may cross 1 room border, but never 2. So it may not run through 3 rooms.
Quirk uses the classic rules of the puzzle.
A worked example
The board is 3 by 3. Each row is its own room. The top room shows 1, the middle room shows 0 and the bottom room shows 2.
- The bottom room needs 2 shaded squares out of 3. Shaded squares may not touch side by side.
- So shade both ends of the bottom row. The middle square of that row stays white.
- The middle room shows 0. Keep all 3 of its squares white.
- Now look down the middle column. Its middle and bottom squares are both white.
- If its top square were white too, the white line would run through all 3 rooms. That crosses 2 borders, which is not allowed.
- So shade the top middle square. That is the 1 shaded square the top room needs.
- Keep the other 2 squares in the top row white.
- Check: no shaded squares touch side by side, and all white squares join up through the middle row. The puzzle is solved.
Without the white line rule, the top room could use any of its 3 squares. The line rule is what makes the answer unique.
Beginner techniques
Start with the zeros
A room that shows 0 has no shaded squares. Keep all its squares white. This gives you a safe start.
Look for tight rooms
A room with little space and a big number often has only one way to fit. A row of 3 squares that needs 2 shaded can only use both ends.
A 2 by 2 room that needs 2 shaded must use 2 squares on a diagonal.
White around shaded
Every square next to a shaded square, side by side, must be white. Mark these as soon as you shade a square.
Break long white lines
Look for a straight white line that would cross 2 room borders. Somewhere along it, a square must be shaded. If only one square can break the line, shade that one.
Keep a way out
Before you shade a square, check that no white square gets closed in. A white square in a corner needs at least one white square next to it. If shading would cut off white squares, keep that square white.
Common mistakes
- Shading 2 squares side by side.
- Thinking a white line may not cross any border. Crossing 1 border is fine. Crossing 2 is not.
- Checking only the columns for long white lines, and forgetting the rows.
- Treating a room with no number as if it shows 0.
- Closing in a white square, often in a corner or along the edge.
Questions
What does Heyawake mean?
The name is Japanese. Heya means room, and wake comes from the word for divide. It fits the puzzle, because the grid is divided into rooms.
Do I have to mark the white squares?
No. In Quirk you can leave squares open. They count as white when the board is checked. Marking them can still help you keep track.
Is Heyawake like Hitori or Kurodoko?
They share two rules: shaded squares never touch side by side, and all white squares stay joined. The difference is what tells you where to shade. In Heyawake, it is the rooms and their numbers.
Does every puzzle have one answer?
Yes. Every Heyawake board in Quirk has exactly one answer. You can find it by thinking, step by step.
What sizes are there?
The easiest boards are 4 by 4. Harder boards grow up to 8 by 8, with more rooms.
Is it good for beginners?
Yes. Rooms with 0 and tight rooms give an easy start. Short lessons in Quirk show each idea on a small board.
Related puzzles
Playing it in Quirk
Tap a square once to shade it. In Quirk, a shaded square looks like a dark pot of soil. Tap again to keep it white, shown as a pebble on moss. Tap once more to clear it.
Drag over several squares to give them all the same mark as the first one. Hints, undo and reset are there if you get stuck.
