Masyu

Masyu can be classified as a classic Japanese puzzle game, the goal of which is to find the right path on the playing field. Numbers, letters and any other symbols are not used here. All that the player sees are white and black circles placed in individual cells of a rectangular (usually square) grid.

The task is to lay a solid contour (broken line) through all these circles without breaking the game rules. That is, to form a conditional Masyu from black and white pearls.

General rules

The puzzle is considered solved if the player managed to draw a non-intersecting broken line through all the circles on the playing field and close it (connect the beginning and end). In this case, two fundamental rules must be observed:

• Always pass through white (empty) circles in a straight line.
• Always pass through black (filled) circles at a 90 degree angle.

If you imagine white and black circles as sections of the road, then the first ones are always straight, and the second ones are turning ones. Drawing diagonal lines in this game is prohibited, and the turn must always be strictly 90 degrees: right, left, down or up. In this case, only one line can be drawn through one cell, which does not intersect with other lines. You can close the loop only when all other moves have already been made, and a “short circuit” (when there are circles on the field that are not included in the circuit) will be counted as a defeat.

In some varieties of Masyu, the rules are more complicated. For example, in addition to white and black circles, there may be gray circles on the field. The player must decide for himself, as he solves the puzzle, which color they belong to: black or white. In other variations of the game, the cells are not square, but hexagonal in shape, and you need to make turns not by 90, but by 60 degrees.

How to solve the puzzle

To correctly solve the Masyu puzzle, you need to clearly understand the rules and have imaginative thinking. It follows from the rules that if a line enters the white circle from the right, it must necessarily exit from the left, and when entering from below, it must exit from above.

The situation with a black pearl is completely different: if a line enters it from the right, then it should come out from below or from above, and if it enters from above, it should come out from the left or right. Thus, white circles leave players no alternative, while black circles give two possible outcomes.

Having remembered these important nuances, you can move on to memorizing/learning the following game situations:

• If the black circle is located close to the edge of the playing field, it must have one line running along it.
• White circles located at the edges of the grid should have a line running parallel to the side.
• Two black circles adjacent to each other must have two lines on the segment, going from each other in different directions.
• Two white circles next to each other either have two lines running parallel through them, or one running through them after turning to exit the other circle.
• If three white circles are located back to back, they should have several parallel lines.
• Orthogonal black circles should have segments extending away from each other.
• Black circles orthogonally located near the end of a loop that is not moving towards it should indicate that the loop is moving away from another segment of its own.
• If white circles are located along the outer border of the field one cell apart, the loop should turn immediately after passing through these circles.
• If three or more white circles are orthogonally adjacent and collinear, the loop must pass through each of them perpendicular to the line of the circles.

In the form of text descriptions, these unspoken rules can seem complex and unclear, and the best way to understand them is to watch the game of Masyu from the outside. On the Internet you can find many videos on this topic: with detailed descriptions of moves and game situations. However, you can learn to play Masyu on your own: relying on the basic rules and constantly practicing!