The Lord of the Flies would be a good book to discuss comparison-wise with the Hunger Games. In both instances there are kids fighting for their lives in the worth of possible circumstances, but in one the kids are fighting against nature, while in the other they are fighting against their government. Ultimately, kids end up killing each other in both books, but what drives the characters to ultimately win and/or survive? and in each book, is survival deemed by which traits?
