Cross-Mappin' without map pack?

I was playing an game of BTB Slayer after having downloaded the title update and boom “Achivement Unlocked Cross-Mappin’” and I don’t even own the noble map pack required for this achivement, so what’s going on?

TU’s automatically update games to their latest versions. Before there wasn’t any TU for Reach so all of the game’s updates came through DLC. Now that a TU is out all of the DLC achievements come along with it.

As some may know there is a little glitch with the DLc achievements that do not require you play on the DLC maps to get them. Heck, I got most of mine just through custom games. It only works as long as you are using a gametype from matchmaking. Custom gametypes will not work.

> As some may know there is a little glitch with the DLc achievements that do not require you play on the DLC maps to get them.

Not a glitch. That is by design.

> Heck, I got most of mine just through custom games. It only works as long as you are using a gametype from matchmaking. Custom gametypes will not work.

I’m pretty sure that only works for the Defiant achievements…

> > As some may know there is a little glitch with the DLc achievements that do not require you play on the DLC maps to get them.
>
> Not a glitch. That is by design.
>
>
>
> > Heck, I got most of mine just through custom games. It only works as long as you are using a gametype from matchmaking. Custom gametypes will not work.
>
> I’m pretty sure that only works for the Defiant achievements…

This.