# Hashiwokakero

Example of a Hashiwokakero with a grid
Associated solution

Hashiwokakero ( Japanese 橋 を か け ろ Hashi o kakero , German 'Build bridges!' ), Often just called Hashi for short , is a genre of logic puzzles published by the Japanese magazine Nikoli , among others .

## manual

Hashiwokakero is played on a rectangular grid (which is usually not printed) of any size. On some grid places there are circled numbers between one and eight. The numbers indicate how many lines have to arrive at the solution. The aim of the game is to connect all these numbers with single or double lines in such a way that these lines at the end result in a continuous path that reaches all number fields.

The following rules apply:

• The lines run horizontally or vertically.
• The lines must not cross each other.
• Each line ends with a number.
• There are only single and double lines.
• Each number field indicates how many lines begin or end at this point.

Due to the German translation of the term Hashiwokakero to 'build bridges', the number fields are often referred to as islands and the lines as bridges .

Usually, the solution or the path sought is clearly defined by the given numbers.

## history

The first Hashiwokakero appeared in Puzzle Communication Nikoli 31 (September 1990), a forerunner of the puzzle appeared in issue 28 (December 1989).

## Solution strategy

To solve a Hashiwokakero, one typically tries first to determine small fragments of the path sought, which can then be gradually connected to form larger parts. For example, a field with a number eight must have double lines in all four possible directions. Likewise, two fields with the number one must not be connected if there are further number fields, otherwise a connected path is no longer possible. Even more rules can be found through logical considerations.