There are no small children in Oxford; the place is entirely populated by students, academics who used to be students, and tourists.
The surrounding villages are fairly normal though. By which I mean typical English home-county.
ETA: But Harry is in no means typical. Unless something awful happens to these kids at puberty, there just aren't enough player characters at 18 for Harry to be the norm.
However, I think they'd be good enough examples that Harry PVE could be expected not to talk in American slang.
- This thread has run its course. You will find newer threads in the discussion section.
Another discussion thread - the fourth - has reached the (arbitrary?) 500 comments threshold, so it's time for a new thread for Eliezer Yudkowsky's widely-praised Harry Potter fanfic.
Most of the paratext and fan-made resources are listed on Mr. LessWrong's author page. There is also AdeleneDawner's collection of most of the previously-published Author's Notes.
Older threads: one, two, three, four. By tag.
Newer threads are in the Discussion section, starting from Part 6.
Spoiler policy as suggested by Unnamed and approved by Eliezer, me, and at least three other upmodders:
It would also be quite sensible and welcome to continue the practice of declaring at the top of your post which chapters you are about to discuss, especially for newly-published ones, so that people who haven't yet seen them can stop reading in time.