Masyu

Masyu (JapaneseましゅMashu, dt bad influence ) is a mystery, which is published by Nikoli. It is also known under the name pearl necklace or scouts.

Regulate

Masyu is played on a rectangular grid. Some squares contain a white or black circle.

The aim of the game is to draw a closed path through all circles The following rules apply:

• The path enters and leaves a square always an edge
• The path can not intersect itself
• White circles are traversed in a straight line, but the path must turn 90 degrees before or after the white circles
• Black circles lie on a curve which turns through 90 degrees. The boxes next to the black circles are run in a straight line.

History

Masyu first appeared in Puzzle Communications Nikoli 84 under the title Shinju no Kubikazari (真珠 の 首飾り, pearl necklace ); time still without black circles. The version with additional black circles first appeared in issue 90 under the name Shiroshinju Kuroshinju (白 真珠 黒 真珠, black and white beads). The name Masyu is based on an in-joke in the publisher Nikoli.

Variants

• Instead of a closed path can also be a way of searching from a starting point to a destination.

• There are additionally or exclusively gray dots and the solver has to find out if these are white or black

• The diagram is a torus, that is, left and right margins and top and bottom margins are stapled together.

• The diagram is divided into areas; the trail must turn at least once in each area.