Editing Shannon switching game (section)

==Variants==

Versions of the Shannon switching game played on a [[directed graph]] and an [[oriented matroid]] have been described for theoretical purposes;<ref>{{cite journal|last1=Hamidoune|first1=Yahya Ould|last2=Las Vergnas|first2=Michel|author2-link= Michel Las Vergnas |title=Directed switching on graphs and matroids|journal=[[Journal of Combinatorial Theory]]|date=1986|series=Series B|volume=40|issue=3|pages=237–239|doi=10.1016/0095-8956(86)90083-3|doi-access=}}</ref><ref>{{cite conference|first1=A. P.|last1=Cláudio|first2=S.|last2=Fonseca|first3=L.|last3=Sequeira|first4=I. P.|last4=Silva|title=Dynamic, Games and Science: International Conference and Advanced School Planet Earth, DGS II, Portugal, August 28–September 6, 2013|series=CIM Series in Mathematical Sciences|editor1-last=Bourguignon|editor1-first=J.-P.|editor2-last= Jeltsch|editor2-first= R.|editor3-last= Pinto|editor3-first= A.A.|editor4-last=Viana|editor4-first= M. |date=2015|contribution= Shannon switching game and directed variants |publisher=Springer|isbn=978-3-319-16117-4|pages=187–199|doi=10.1007/978-3-319-16118-1_10}}</ref> but no corresponding commercial games have been published.

===Gale===
[[File:BridgeIt2.svg|thumb|A win for red in Gale]]
In this game invented by American mathematician [[David Gale]] and described in [[Martin Gardner]]'s column in ''Scientific American'' Oct. 1958, two grids of differently-colored dots are overlaid at an offset. One player links orthogonally adjacent dots on one grid, and the other player uses the other. One player attempts to link the top of their grid to the bottom, while the other tries to link their left side to the right.  The game is equivalent to the Shannon switching game played on a rectangular grid.  No draw can result; the first player can always win with correct play.

A commercial board game implementing the scheme was marketed in 1960 by [[Hassenfeld Brothers]] under the name Bridg-It.<ref>{{bgg|11052|Bridg-it}}</ref> The game consisted of a plastic board with two interleaved 5x6 rectangular grids of pedestals (one set yellow, the other red), two sets of 20 each red and yellow plastic bridges, and matching pegs to mount them on.  Players alternate placing a bridge across any two adjacent pedestals of matching color until one player connects the two opposite sides of the board marked in the player's color.  A variant of the game is described in the instructions: each player gets a limited number of bridges, say 10.  If neither player has won when all the bridges are placed, a player in his turn, may reposition one of his bridges until a winner results.  The game is long out of production.

An electronic implementation of the Game of [https://ludii.games/details.php?keyword=Gale Gale] is available in the [https://ludii.games/index.php Ludii Games Portal].