Just read the last few posts and realized I don't even understand how one becomes a ghoul. It's a slow process, correct? How does it differ from radiation poisoning and why didn't they just die? What was so different that made them continue to live as a ghoul?
It's been disputed a lot, really. In Fallout 1, all ghouls came from one place. They came from the vault that was located in Bakersfield, nowadays known as Necropolis. I think there was a mix of FEV and extreme radiation exposure to turn one into a ghoul at first. Then it was changed to just radiation, so that not all ghouls had to come from Necropolis because if their population got slaughtered (or was that canon?) that would mean there'd be no ghouls in future games, just like super mutants also was dying out. But the super mutants were also changed so that we got loads of them and loads of ghouls in Fallout 3. So all ghouls were made by extreme radiation exposure, except for Harold.
Anyways, what I thought, up until Moira Brown, was that ghoulification was a one chance in a hundred, and the process took months to years. Clearly, it's instantaneous, and Obsidian went with that too with Camp Searchlight and whatnot?
What I don't like is how there can be "new ghouls". I liked it that all ghouls were old ghouls, people who survived the two hour nuclear firestorm and radiation exposure and weren't fortunate enough to die. That it was the war that caused them, and that they were just like zombies in appearance, flesh falling off, organs and bones showing, slow and shuffling, face horribly disfigured... now they can be made by just living too long by a leaking waste barrel or something, and they just look like they got a 3rd degree burn all over their body and not like they've mutated. Guess this rant don't answer your question though, how they are made. Since I've already answered that, I think, I am sorry
If it were to be ingame, the option to be a ghoul, then you would have to start out as one and not become one in the game because I don't like the "stand in radiation till your reach 1000 and turn ghoul"-idea. That is stupid, it'd kill anyone who tries it. It needs someone surviving a nuclear blast imo, kind of like Moira Brown, but not instantaneous like that.