Halo 3/Halo 3: ODST achievements?

[Jesus Junior]

I bought the legendary map pack for halo 3 but I skipped the mythic map pack, so I heard ODST has all of the halo 3 maps so when it comes out. Will I still be able to earn mythic achievements on halo 3 while playing ODST? Thanks

 

[VideoGamer983]

No. Halo 3 ODST is a standalone disk and it will come with a code or disk of some sort and you will be able to download all the maps for Halo 3, so you can earn the achievments but youll have to wait till september