Ok,first off,I know how annoying this sounds asking if it matters if I play this game before Halo 3,I don't like playing games out of order either. I'd like to play Halo 3 first,but I don't have spare money to spend on it. I got ODST with a new 360 package.
But anyway,I was wondering in this case does it really matter if I haven't played Halo 3,I know there not very heavy with there stories,so I figure I can just play this and then eventually pick up Halo 3.
And I hear this takes place during the Halo 3.Is there any spoilers in this game that happened in Halo 3?
Just curious on your guys thoughts?
So does it really matter in this case?

No. Chronologically ODST comes after the end of the level Metropolis in Halo 2 anyways. It only has the Halo 3 moniker because it uses the same engine. Completely self contained.

This takes place between Halo 2/3. I am a big Halo fan, so I would say you should play 1,2, and then 3, and THEN odst. However, odst is a companion to Halo 3, and a story cut off all in itself. You should be fine.

" No. Chronologically ODST comes after the end of the level Metropolis in Halo 2 anyways. It only has the Halo 3 moniker because it uses the same engine. Completely self contained. "

Alright,thanks for the help guys.
I'll probably just play ODST,and then play Halo 3 whenever I get it.