Thud or Cyvasse

Apart from chess variants that exist in the real world, there are a number of chess like games that exist in the world of literature. "The Glass Bead Game" (Hermann Hesse) is a famous example of this, imagining a society where the mastery of the game is an end to itself.
"The Player of Games" by Iain M. Banks has similar themes, although mastery of a number of different games is required by Gurgeh, the stories hero, before he embarks on a quest to defeat another civilization whose entire order is built around a game called Azad.
Some games in literature have become real world games themselves. "Thud" from the Terry Pratchett book of the same name is one example, although the game is similar to the Norse game of Tablut. And there is even a game that has come from Game of Thrones, called Cyvasse. It has most of the GoT elements in it (Dragons, Kings, Knights) although the rules I have seen seem a bit light on the gratuitous nudity the the television series has. Interestingly, the version I have come across may not be the only version out there, as further searching has thrown up a couple of others.
As with most of these "Disrupt Chess" inventions, they don't actually do that, but if you are trying to out nerd your nerd friends, mastery of one of these games may win you a tankard of mead at the next comics convention.