Hmm, a long shot but is it maybe "The Player of Games" by Ian M. Banks (1988)? While it doesn't happen on Titan, the main character (a skilful player of board games) participates in tournament of a very complicated strategic game:
Although the actual rules are not given in the book, the game is primarily tactical and played on three-dimensional boards of various shapes and sizes. Typically the boards are large enough for players to walk around inside them to move or interact with their pieces. The number of players differs from game to game and also influences the tactics, as players can choose to cooperate or compete with one another. As well as skill and tactics, random events may influence gameplay (often as card or other games of chance), and sometimes may change the outcome critically.
The game consists of a number of minor games, such as card games and elemental die matching, which allow the players to build up their forces for use on the game's three giant boards (in order: the Board of Origin, the Board of Form, and finally the Board of Becoming) and a number of minor boards.
The game uses a variety of pieces to represent a player's units (military, resource or even philosophical premises). Some of the pieces are genetically engineered constructs, which may change form during the game according to their use and environment.
The tournament is very prestigious and the winner will be proclaimed the new emperor.