Triangular chess

Triangular chess refers to a group of chess variants played on boards composed of triangular cells. 
The best known is a chess variant for two players, Triangular Chess, invented by George R. Dekle Sr. in 1986. Dekle made another variation including fairy pieces which is called Tri-Chess. These two two-player games were included in "World Game Review" No. 10 edited by Michael Keller.
Russian Ilshat Tagiev, who introduced a "neutrality rule" to three-player chess in the mid-2000s, took out a patent for a three-person variant of triangular chess on a hexagonal board in 2009.
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