I think your attempt to coin the new terms invisible and visible railroad will probably fail.
I wasn't even the first person to use it in this thread. And a quick Google reveals the term "invisible railroad" has been used since at least 2005. Google Groups indicates usage dating back more than a decade.
You might try reading the thread. It's not that hard and it's a lot easier than me re-posting the same crap every three pages because you can't be bothered.
Good heavens. Really?
Lemme know when you're interested in having an actual discussion. Right now you're just trolling.
I was wondering about this. In several places, 1974 OD&D says the GM must have a mega-dungeon ready before play can begin. Wilderness and town adventures are also discussed but they are more of an adjunct to the centre-piece of play, the dungeon, which is vast.
I'm going to dispute this. While the megadungeon was clearly a very important part of the game, the original White Box included more rules for non-dungeon play than for dungeon play. And some surprising aspects of the rulebooks had a primary focus on non-dungeon play. For example, the class descriptions. And the monster listings. (You weren't generating 30-300 goblins as a random encounter for the dungeon.)
In many ways, I think it can be argued that OD&D was the edition of the game which was least focused on the "kick down the door" style of play.
Although, ironically, it's also the edition of the game which serves as the strongest proponent for the megaduneon.
I don't view this as a contradiction.