What board game does Nick compare his battle with Mrs. Granger to in Frindle?
Nick compares his battle with Mrs. Granger to a game of chess.
Nick has chosen to challenge Mrs. Granger's authority by inventing the word "frindle." When confronted by his teacher about the disruption his actions are causing, Nick boldly chooses to defend his position, arguing that all words are made up by someone, and enter the lexicon through accepted use. Although Mrs. Granger seems to be secretly amused, she chooses to play the part of the adversary, parying, in the name of order, Nick's every attempt to spread the use of the new word. Nick and Mrs. Granger are intelligent and courageous adversaries, each one making move after move to promote his or her agenda, while the other does his or her best to counter the latest advance. In thinking about what is going on, Nick has
"a sudden vision of what (is) really going on here. It (is) a chess game, Nick against Mrs. Granger."
Mrs. Granger has tried to get Nick to stop his shenanigans by having the principal, Mrs. Chatham, come to his house and talk to his parents. Nick interprets this move as Mrs. Granger's attempt
"to end the game by using her queen - Mrs. Chatham in her black raincoat, the black queen."
What neither Nick nor Mrs. Chatham know is that Nick also
"has a powerful defender of his own - good old Mom, the white queen."
Nick's Mom defends him in front of Mrs. Chatham, and Nick realizes with delight that
"the game (is) not over. It (will) go on until there (is) a winner and a loser" (Chapter 9).