you buy them on xbl marketplace, it has nothing to do with beating it.
no
If by "halo 3 maps" you mean the Halo 3 Heroic, Legendary, Mythic and Cold Storage maps, then yes. However to play campaign levels, you must actually advance in the game to get to them.
foundation beat campain on heroic
The Heroic Maps, Cold Storage, and Legendary Maps are Required. The Mythic Maps, however, are not.
A legendary map is from the legendary map pack that can be purchased for 800 Microsoft points. The legendary maps are ghost town, blackout and avalanche.
beat the game once on any difficulty
there are many unlockables in halo, there are:-skulls, 1 to 2 on each level-armor changes, depending on what you do (spartan officer, all skulls...etc)-katana or sword-on-back, 1000 gamerscore (from halo only)-maps, heroic maps for 800gamerpoints not score (new legendary maps coming out)that's about it if you want specifics on armor requirements Google itthese are about it.....
In order to unlock all of the halo 3 maps you must purchase them from the halo 3 marketplace... heroic map pack is free, cold storage is free, and legendary map pack is about 600 live points...
You need all maps( Heroic, legendary, and mythic) to play on the playlist cold storage is optional but not needed.
You can't. The Mythic Maps our only playable on Halo 3, not Halo Wars.
You go on the map you made it on and it should be on that map type
haw to make mode maps in halo 3