The Player of Games - Iain M Banks (Book 2 in the Culture series)

The Culture - a utopian human-machine symbiotic society - has thrown up many expert Game Players, and one of the greatest is Jernau Morat Gurgeh. He is Master of every board, computer and strategy - he is The Player of Games. Bored with success, Gurgeh travels to the cruel and incredibly wealthy Empire of Azad to try their infamous game... a game so complex, so like life itself, that the winner becomes emperor.

Mocked, blackmailed, almost murdered, Gurgeh plays the game, and faces the challenge of his life - and very possibly his death.