how do I play custom games on halo 3 without people that aren't on my friend list?

[nickcool30]

i want to set up the match and settings but how do i join custom games or run them with people not on my friend list. I WOULD ALSO LIKE TO KNOW HOW TO DO THIS IN CAMPAIGN AS WELL
PLEASE HELP ME

 

[Crazedburro42]

you cant host a campaign game or custom game its only open to friends and friends of ur freinds and the freinds of ur friends and so on