I'm looking for a novel that I read in the early 2000s, about a normal girl who is transported into a magic kingdom.
Chess is a big part of this world, and it's somehow tied to magic. The girl has to go through trials and adventures in a court, and defeats the villain in the end with a chessboard. I believe at the end of the story, she's also able to travel back and forth between the real world and the magic one.
I think it was a standalone book at that point, but I am unsure if there are any sequels since then.