A Long Time Ago....
I started on my "Masterpiece", a Human in Equestria epic called "Last". All you need to know for this discussion is that the first chapter features no humans and takes place during and immediately after the final scene of the first-season episode "Dragonshy". Twilight Sparkle has just dictated her letter to the Princess ("Friends can be an amazing source of strength...") and has been called outside by Applejack. We see Spike re-reading the letter, and when Twilight returns from the antics outside, he asks her some follow-up questions about what she learned.

Because I wanted to guarantee that this story that was burning inside me got a real chance to shine, I approached an editor, FiMFiction user KeatsLocksley, to do some proofreading for me on this initial chapter to ensure it was fit to be seen. For those who like heartwarming stories, I'll say that Keats and I have since grown to be friends, and that he's still working with me on "Last".
Keats gave me a lot of feedback on that first chapter. What caught me most by surprise was his suggestion that I describe the room Twilight Sparkle and Spike were in.
When I read that, I was all like, .
I just naturally expected everyone reading to be so familiar with the show that I wouldn't need to describe where the last scene of "Dragonshy" took place. Just off the top of your head, do you remember? Do you remember what happened outside with Rainbow Dash, Pinkie and Fluttershy? If a chapter opens with text lifted directly from one of the friendship reports from one of the episodes, would you recognize it and be able to figure out which episode it was?

We're all fans of the show. It's really not necessary for us to describe to the reader what Applejack's colour is, or where Rarity works, or that Apple Bloom's hair bow is the cutest thing in the whole Universe, so where's the boundary? Is there a boundary? Or am I just spouting nonsense because I've had my first late-night homework session less than a week into the school term last night and I'm sleepy?

Any help with any of the technical or personal problems mentioned above would be very much appreciated, and lively discussion is hoped for.

At the beginning of anything, explanation is a must.

971232
So what you're saying is I'm tired and should go to bed.

I like the way you think.

971224 Personally, I'll recognize it, but I'm lifting parts of episodes for my story Polygamy is Magic as is. I can't really say for sure about everyone but some will. You'll want to set the scene a bit more than just opening with Twilight's letter to Celestia.

I have a couple readers of my story who have never seen the show. So I'd say explanation is useful. It also gives the piece atmosphere and a sense for your own writing style.

971224 I remember what happened at the end of the episode and could probably figure it out with what details you give. I don't remember the room Twi was in (though it was the library, so there is that). I think the issue here isn't so much losing readers on locations but the slightly rushed feel of the opening. It's mostly dialogue, and taking the time to describe things will give the reader a chance to become immersed in the story, rather than feeling like he/she is just being thrown in. That's where you're more likely to lose readers, in my opinion. Granted, I kinda skimmed it, so I may be a little off.

Also, commas always go within quotation marks. If you end with a period, question mark, or exclamation point, you do not need a comma.

971251
Well, thanks for skimming it.

It's a bit tricky, but here's my take on it. You should probably assume that the readers are familiar enough with the franchise that you don't need a three page dissertation on Equestria and its residents before anything actually happens (I'm looking at you The Hoobit!), but at the same time, some exposition and description is generally expected, to set the scene if nothing else. For example, if you were to read the Harry Potter series again, you might notice that as far as book 6, whenever the Griffandor House common room is introduced, we are at the very least reminded of it's size and general hominess.

Briefly (and that is the term to take into account here, briefly) describing the area not only fully establishes where, when, and why things are happening better than "One evening in Twilight's library," but also can give clues as to the general mood. If the library is immaculately clean, then Twi likely just finished book sorting or something and would be in a very good mood, with a very tired Spike. But if it's a mess, with books everywhere, then Twi could very likely be in the middle of a study project--either for simple academic advancement on her own, or for something much more urgent. Just as an example.

971224
On one hand, you can reasonably expect people reading pony fanfiction to recognize and know the baseline Equestria presented in the show. So, main characters, more important supporting characters, basic locations.

However, expecting them to recognize what episode a friendship report was from or the room that the ponies were standing in during a particular episode is way too far. In addition, it's bad writing to not describe settings, regardless of whether we've seen the episodes or not. It gives us context, an image in our head. Immersion.

If it's a simple question or detail, you can reasonably expect the reader to know it. (What is the orange apple horse's name, what color is Rarity, what is the thing that hangs around with Twilight Sparkle and sends letters to the princess for her, how many princesses are there right now, etc.)

If it's a more involved detail that would require actually memorizing scenes of the show (Contents of Friendship Report #17, what Twilight's room looked like in a certain episode, how many background ponies were in the shot when Celestia got wreckt by Chrysalis) then you're pushing the line. Some might know it, but it'd only be the obsessive fans.

971251
I think you were right on with your analysis.

That first chapter has always bugged me. I think you might have figured out why for me.

Thanks a lot. It's been tough getting feedback.

971309
I think you've answered my question the best. Basically what you're saying is that if the scene is described well enough, then reader familiarity becomes a non-issue.

I'm well aware there's a difference between knowing the general layout of the world that's seen in every episode, and the minute details that are mentioned once and are only caught by the most vigilant viewers.
What's important is that it reads well as a story, and not just some novel spin on what we're familiar with.
Thanks for the response.

It's not only about reader familiarity. It's about Immersion. To make a reader feel engrossed in a story, you need him to be engaged with your characters and their environment - and thus you must go deep in on both, even if they are familiar with them. Otherwise they'll just read it as a script, not a fic - and there's a reason scripts aren't allowed on this site :)

Apple Bloom's hair bow is the cutest thing in the whole Universe

I take issue with this.
Apple Bloom's bow should not hold that honor.
That honor belongs to the crusaders as a group.

Treat it like any other fiction: Explain everything as needed. Don't lead them by the nose, but if they've never ever seen the show, it should stand up as a fiction piece.

I'm writing two alt universe pieces, so having a mindset where you need to inform your reader about certain events as the crop up helps immensely with transitioning a story from a fan fiction piece into a fiction piece.

Honestly I think saying 'in the library' is sufficient. However, if you want to go above and beyond just sufficient you could go ahead and describe every facet of the scenery, from the amount of sunlight coming in the windows to the temperature outside, to the library-smell of musty old books. (Actually I find using descriptors in addition to just visual appearances always feels nice.) But honestly, it depends on your story. If it's a slapstick comedy, mulling over the wood grain on the walls of the library would be pointless and harmful to the story. If it's a deep and insightful drama, these things help. You'll have to find the balance by yourself for this particular story.

And remember, when you describe stuff, try to 'show, not tell.'

Coincidentally, I also have a HiE called 'Last' or at least that's how I abbreviate 'Last Brony Gets His Wish'

971224

Well, not everyone is a fan on the same level and in the same way. I, for example, STILL haven't seen Season 3. What happened was that I discovered that I had a lot more fun with the comics than I had with the show. Friendship is Magic is just about reaching the point where it can have honest-to-goodness fans that hasn't seen or read all the material yet.

My best suggestion is to aim at the lowest level of familiarity required to understand the fanfic. What I mean is, if the plot is heavily tied to Dragonshy to the point where you NEED to have watched it to understand the story, then you can assume that they know the big plot, but NOT that they know EVERY line of dialogue or can bring up an image of every location in their head.

Basically, assume that the reader is casually familiar with the episodes neccesery for the story, but allow for hazy recollections and faulty memories. I can't be the only one who feels I'm going senile waaay before my time sometimes when it comes to remembering stuff.

971224 It's been a year and a half since I saw the episode, so I wouldn't be able to recall it properly. And I don't really think that I'm the only one.
972697 I agree. I have for example only seen about two thirds of Season 3 either, so any details regarding some episodes would probably be lost on me.

971670
I know of that story. I'll get around to reading it eventually.

I can tell you that my story is completely different from yours though.

973823 lol I wasn't implying anything. You should go read it!

975543
Well maybe you should go read MY "Last" ?!#@ERROR

975543
You'll give it a try, maybe?

982797 I've been meaning to. When I find some free time, definitely will

982867
Thank youThank youThank youThank youThank youThank youThank youThank youThank youThank youThank you

I won't ever put you on the spot like that ever again!
Cross my heart and hope to fly, stick a cupcake in my eye!