Fallout 3, even though I liked it somewhat, has hardly any connection to the original Fallouts. And I'm not only talking about the obvious changes in gameplay. F1 has no level scaling of any kind, nor has it the "every approch can work" or has "failsafe switches" (eg. there is a time limit, you can throw away quest items, you can screw up big time in character builds and you can easily make an "unwinnable save" e.g. radiation poisoning). You have to play F1 (and 2) with a lot more "awereness" than most modern games. While it isn't that oldschool that you
have to use the "ask about" option, you still have to carefully check your surroundings and dialogues. To enter the wastelands, you must be prepared. Ammo, meds, tools. You won't find the object needed for the puzzle conveniently in the next room.
Fallout 3, for better and worse, is somewhat the "Oblivion with guns" everybody called it. F:NV is the proper Fallout 3 imo and a very good game.
And I'm pretty sure the first merchant has a rope...