[quote name='MrNinjaSquirrel']so does anyone know specific games/features that don't work with 14 day trials? I wanted to try halo 3 multiplayer, but all the ranked modes still say "restricted to gold members".[/QUOTE]
I've never seen a "what you can't do on a trial" thread out there, but, typically speaking, when using a trial in the Halo series, you can only join social multiplayer modes, not ranked.
Also, most game modes in other titles that permit a guest account to sign-in will generally require a valid, non-trial, Gold membership. So, as an example, you can do play all of the online game modes in Grand Slam Tennis 2 except for doubles since it requires a guest account to be signed in.