Can one go into settings and deselect (or blacklist, or exclude, or whatever it's called) any number of cards? If there is no limit to the number of such cards, then it should be easy for this person to exclude everything that is not in the Base set, right? (Although maybe a bit labor intensive.) Or am I not understanding this aspect of adjustable settings? (I've never tried to "forbid" any cards, so I'm prepared to be totally wrong about this.) But I thought that was the whole point of the "Familiar Cards" tab that's at the top of the first post-log-in screen, and I thought I remember even seeing a way to easily and quickly exclude entire expansion sets while doing this.