Turned boxes
On most boards the boxes are the shape you expect. On some, they are turned on their side. The rule is the same, but your eyes are not.
What a box looks like
A box is a block of squares outlined in a thicker line, and it must hold every mark once. On a 4×4 board the box is 2×2. On a 9×9 board it is 3×3. On a 6×6 board there is no square block that fits, so the box is a rectangle: two rows tall and three columns wide.
What "turned" means
A turned board flips every box on its side, so that the 2-tall, 3-wide box becomes 3 tall and 2 wide. The total number of boxes is the same, and so are the rows and columns. Only the outline changes.
Why it is a puzzle by itself
You would expect this to be no harder. After all, a box is a box. But after a few puzzles your eye learns to take in the box at a glance, wide and short, and a turned one catches you out. You will find yourself checking a row when you meant to check the box, or counting across when you should be counting down. The effect fades with practice, and then you can play both without noticing.
- Trace the outline with your eye before you start. A few seconds spent seeing where the thick lines are saves several wrong guesses.
- Check the box last. Many players check row and column from habit and forget the box. On a turned board the box is the one most likely to be misread.
- Mark with the bookmark if you suspect you read a box wrong, and try the other reading.
Where you will meet it
Turned boxes arrive at Level 261, with a short explainer and an easy first board. After that they appear on the bigger sizes, turned Double and larger boards in the later worlds, and on some daily puzzles, for example the Friday 6×6 Double. Boards where the box is a perfect square, like 4×4 and 9×9, cannot be turned, because a square looks the same on its side.