What is "Trace Italian" in the novel, Wolf in White Van?

Trace Italian is the imaginary role-playing game (similar in some ways to Dungeons and Dragons) developed, marketed, and run by protagonist Sean Philips. On one level, the choice-defined journeys made by the game's players (and the consequences of some of those choices) form important foundations for the novel's plots. On a symbolic level, the quests of the game players for a truth that the game master (Sean) says they will never actually reach metaphorically represents Sean's own movement towards a truth that, in contrast to the truth at the core of the game, he actually DOES reach.