Clam Science - We do what we must, because we can.

The movies were fun, but did either of you read the book? The only thing the two had in common were the main character's names and bugs!

As noted earlier up thread, the exisitance of a bible helps maintain consistancy between spin-offs. Think if the universe contradictions in the orignal Star Trek series, let alone those coming out of other series, countless books, etc.

Remember, there are also Halo books and a ARG chock full of material that has to be considered.