how to play on xbox live in halo 3 odst campaign?

[Leroy]

i wanna be able to play with random players not just my frirends please help

 

[mr_j526]

That would require some sort of matchmaking system which is only usable in the online matchmaking system on Halo 2 and 3 (don't think it was included in Halo 1, but I can't say for sure). Halo 2 and 3 only had campaigns that were playable with friends, and ODST continues that trend. About the only way to get random people to play with you in campaign would be to ask on a forum or on here, you will likely have to make them a friend in order to play with them, but it will be someone different from the rest of your current friends list. The same principle works with ODST firefight mode, there's no matchmaking system included there.