Set in a dystopian future where each couple who wants to have a child is paired up with another couple who wants to have a child. Their collective DNA is combined and two identical children (Alts) are conceived. The Alts are raised apart and at some point between their twelfth and eighteenth birthdays they are "activated" which means that each is sent to kill the other. The (somewhat fuzzy) reasoning being that the society wants only the strongest to survive, thus ensuring a population that can withstand threats. They're not entirely clear on what those threats may be. Also, families had four and five kids each. If you knew your child was going to have slaughter or be slaughtered (or be killed in the cross-fire as several of the main character's family are) what would really be your motivation to have a mess of kids? Nagging plot holes like this riddled this story. The basic premise wasn't bad, there just wasn't enough framework. It's like the author wanted too badly to jump into the shooting and never laid a real foundation for anything to make much sense.
I know kids killing kids worked brilliantly in the Hunger Games but it's because the reasoning behind it was so clearly defined. The government was the villain manipulating the people. In "Dualed", we don't get nearly enough "why" behind tons and tons (and tons) of violence. I kept thinking that at some point the whole (vague) system of Alts would be challenged, but no... the kids just keep killing each other.
I love a good dystopian but it has to make sense.