Anderson, M. (2004). The Game of Sunken Places. New York: Scholastic Press.

Gregory and his friend Brian go to visit Gregory's Uncle Max.
The boys are soon thrown into a dangerous and confusing game.
The boys think it's a board game, but it turns into much more.  Soon they are involved in time travel, battling along side trolls, visiting ancient empires.  Brian ends up winning the game, but a new adventure is around the corner. I would recommend this book for ages 8 through 14.  This book reminded of the choose your own adventure books that I read as a child. Although the reader can't choose their own adventure, there is so much going on in the book, that it's one adventure after another.