» Fri Jul 09, 2010 10:15 pm
It's slang: to say that something is 'vanilla' means that it's the plain or regular version. Like vanilla ice cream; that's the flavour you default to when you think of ice cream. So, here, it would refer to the more original version of Fallout 3, in contrast to the addition of something like mods, the DLCs, or maybe even the update patches.