You should play the campaign it's not good as halo 2 or halo 1 but it's still good and you should just play for fun(recommend heroic because lots of different types of enemies come which you don't see much on easy/normal) also so you can get used to using the weapons and ready for multiplayer Then you should go to multiplayer and play alot because it's awesome unlike reach but slowly play through the campaign and get the skulls then complete it on legendary! Campaign is much easier on legendary than other games so that is a bonus NEVER FORGET CAMPAIGN IT ALWAYS COMES FIRST! and REPOPULATE HALO 3! Okay I think I made my point...