I remember getting the first three Halo books and reading them when I was a hyped 13 year old crossing fingers for a Halo 2 PC release. The prequel book, [i]Fall of Reach[/i], was a very informing about the circumstances leading to the opening of Halo. [i]The Flood[/i] was an interesting canon telling of the campaign story; the details included flesh out the story beyond what technology and time constraints at Bungie would allow back in the day. And then, [i]First Strike[/i] showed the in-betweens of Halo and Halo 2, without which the abrupt start of Halo 2's campaign is no longer disorienting. It also showed a tiny bit of philosophical/sentimental engagement by the Chief you'd never get to see in the games before Halo 4. For me, I valued how the books augmented what I understood about the game and the circumstances being experienced outside of my own. Books can connect dots, enhance our appreciation for certain characters, and create additional depth that hints at what's to come without having to negotiate a way to shove it in our faces in-game when it isn't important yet (e.g. the Chief activating the underground Forerunner bridge). Having supplementary material like that is enriching and good for your brain. Unfortunately, it also is a hassle for the "literary casual" to read it, so whatever is made exclusive to the book needs to be non-essential to understanding what is happening in the game. Ideally, hints of EVERYTHING would be present in-game, but I don't know how much Dark Souls they're gonna want to shove into Destiny.