Would you confuse a game called "Brothers" with "Super Mario Brothers"?
Would you confuse a game called "Duty" with "Call of Duty"?
Would you confuse a game called "Fantasy" with "Final Fantasy"?
Would you confuse a game called "Evil" with "Resident Evil"?
Not that I'm on Bethesda's side here, but there's a section in
this Wired article that points out that they do have a legitimate case here.
“The basic question here is whether the two trademarks are likely to be confused,” Methenitis said in an e-mail... While hard-core gamers would generally know the difference between Scrolls and The Elder Scrolls — one is a card game and the other is an epic fantasy adventure — Methenitis says average shoppers might think the two are related, since both titles include the word scrolls, both are games and both have similar fantasy themes (at a very shallow level).
So these comparisons, eiyukabe, are valid if the games have no thematic similarity. But if there was a game called "Brothers" about plumbers, stomping on mushrooms or rescuing princesses you might have an issue. A game called "Evil" about killing zombies, or an army game called "Duty" could reasonably be trademark infringement, as it's clearly possible to confuse them, or at very least think they're from the same product line.
I can see why Bethesda has a case here, and in trademark law, as Miguelito points out, your trademarks don't stand up if you don't guard them. That doesn't necessarily mean they should or would win the case though. I personally think "Scrolls" is perfectly reasonable.
Of course, if they lost the name or had to change it to "Scrolls of ____" or something, I don't think that would be a big issue for them. It's not as if they have a lot of marketing material out there with the "Scrolls" trademark on it already. After all, the game's not even out yet!