Masyu is also called Pearls. The pearls are black and white circles in some of the boxes.
The rules
- Draw 1 closed loop. It goes from box to box, across or up and down, never on a slant.
- The loop passes through every pearl.
- The loop never crosses or touches itself. It goes through each box at most once.
- At a black pearl, the loop turns. Then it goes straight for 1 more box on both sides of the turn.
- At a white pearl, the loop goes straight. It must turn in the box just before or just after the pearl, on at least 1 side.
- The loop does not need to visit empty boxes. You can skip them.
These are the classic Masyu rules. In Quirk, each box is shown as a hole, and the loop runs from hole to hole.
A worked example
This board has 3 rows and 3 columns. There is a black pearl in the top left corner and one in the bottom right corner.
| Column 1 | Column 2 | Column 3 | |
|---|---|---|---|
| Row 1 | Black pearl | ||
| Row 2 | |||
| Row 3 | Black pearl |
- The black pearl in the top left must turn. In a corner, the only way to turn is right and down.
- After a black pearl, the loop goes straight for 1 more box on each side.
- So the line to the right goes on through row 1 to column 3.
- The line down goes on through column 1 to row 3.
- The black pearl in the bottom right works the same way. It turns left and up.
- Its lines go on along row 3 to column 1, and up column 3 to row 1.
- Now the lines meet in the other 2 corners. The loop runs around the edge and is closed.
- The middle box stays empty. That is fine, because boxes without a pearl can be skipped.
Now take the same board with no black pearls. Put a white pearl in the middle of each side instead.
- The white pearl in row 1, column 2 must go straight. There is no box above it, so it cannot go up and down.
- So the loop goes across row 1 through this pearl.
- The other 3 white pearls also sit on an edge. Each one must run along its edge in the same way.
- Join these lines, and they form a loop around the edge of the board.
- Check the white pearls. Each one has a turn in the corner boxes on both sides. At least 1 turn is needed, so 2 is fine.
Beginner techniques
Black pearls near the edge
A black pearl needs 2 boxes of straight line on each side it uses. So a black pearl in row 1 or row 2 cannot go up.
It must go down 2 boxes instead. The same works for every edge of the board.
White pearls on the edge
A white pearl on the edge cannot go straight out over the edge. So the loop must run along the edge through it.
Three white pearls in a row
Say 3 white pearls sit next to each other in a row. If the loop ran along the row, the pearls on both ends would go straight too. Then the middle pearl would have no turn next to it.
So the loop crosses each of these 3 pearls straight up and down.
Mark lines that cannot be there
Put a cross between 2 boxes when no line can go there. Crosses make it easier to see where the loop must go.
Do not close the loop too early
The loop must pass through every pearl. If a line would close a small loop and leave a pearl out, that line cannot be there.
Common mistakes
- Turning in the box just next to a black pearl. Both sides must go straight for 1 box.
- Going straight through a white pearl with no turn on either side.
- Thinking a white pearl may turn on only 1 side. Turning on both sides is fine.
- Trying to pass through every box. Empty boxes can be skipped.
- Making 2 separate loops. All lines must join into 1 loop.
Questions
Is Masyu the same as Pearls?
Yes. Pearls is another name for this puzzle, with the same black and white pearl rules.
Do I have to use every box?
No. The loop must pass through every pearl, but it may skip boxes without a pearl.
How is Masyu different from Slitherlink?
In Slitherlink, the loop runs along the lines between boxes. In Masyu, it runs through the middle of the boxes.
Does every puzzle have one solution?
Yes. Quirk checks that each board has exactly 1 loop that fits all the pearls.
What sizes are there?
Boards are small, no bigger than 7 by 7 boxes. Harder boards are bigger and have more pearls.
Is Masyu good for beginners?
Yes, once you know the 2 pearl rules. Start at the corners and edges. A hint shows which lines must be on or off, and why.
Related puzzles
Playing it in Quirk
Tap between 2 holes to lay a line. Tap again for a cross, which means no line. Tap once more to clear it.
On a bigger board, you can enlarge it and later show the whole board again. If a pearl's rule is broken, Quirk tells you which rule.
