I disagree that (A)D&D was a very American thing. Certainly in Norway and Sweden it was huge (or at least as huge as pen & paper rpgs can be) when I was growing up. Sweden did have its own RPG home grown scene going on with both the other D&D (Drakar & Demoner) and Mutant being quite popular, but on the whole I'd say AD&D was by far the most popular game.