Recently I have been thinking about What I Said in regard to A Theory Of Fun and now I think I can articulate better what Raph is trying to say in his book and why I disagree with him (hence the revisit).
From his point of view all games teach the gamer something. Wither it be dropping blocks in Tetris, galactic domination or shooting people in the head. Every game is a learning experience for the player. He thinks games become boring when the player understands the game's pattern (how the game's rule system works). For this he looks to Tic-Tack-Toe because this is a game that most people become tired of after they gain a certain level of expertise. He mistakingly sees this learning aspect of games and this rule complexity aspect as the catalyst for fun.
He is right in that when a player fully understands the play strategies to a rule-system in a game then there is an opportunity for that player to become board, but a rule-system present in any game that the player has not yet mastered or has not learned everything there is to learn about, is NOT the reason why the game is or is not 'fun'. This is where I feel the book's argument completely collapses because he never defines what fun is, it's associated effects (anticipation, gratification, disappointment etc) or why some games are considered fun and others aren't regardless of the learning experience or rule system represented in the game. Instead he spends a lot of the book talking about the cultural significance of games and their relationship to art which is completely subjective.