How does the xp system work in halo 3?

[C.G]

Can someone explain how the exp system works? Like how many kills will earn you how much xp and so on? The reason I am asking is cuz I am making a new xbox live account and I am going to leave it off on 7 exp. So on Wednesday , the 7th, I can unlock the 7 on the 7th Anual achievement.

Thanks

 

[Shane S]

its very simple, as long as you win the game that you played, you automatically get 1 xp. It doesnt matter about how many kills or deaths you have. if you play double exp you get 2 xp every time you win a game