Here's one that's short, but it at least makes the minimum amount ot be a story: https://chyoa.com/story/I've-never-done-that.5044.
This, though. This. This is so monumentally an example of what we're talking about that it deserves to be left untouched, for us to marvel at. https://chyoa.com/story/Decisions-at-the-Frat-Party.2665
I am starting to think that maybe having some kind of warning that just says "Hey it doesn't look like you have written enough just yet." Really with a intro I would say you are gonna have a minimum of 500 words to make a decent set up.
All the nope! What if you are interrupted while writing the intro? You've put in all the work on the story premise and what not in the setup page but now have to write at least 500 words before you can save? I THINK NOT!
Introductions are used differently by different authors. Its not rare that they'll simply be a platform to outline a theme, where the real story is around the corner. I've done that...
I like Liz's idea of some sort of minimum word count before publishing. It can even be spread out over all chapters combined instead of just the intro. At least there will be some sort of substance there.
I wouldn't do 500 words to some that is excessive especially if the intro is more of a launchpad. Then of course there are multiple chapters how minimum do you go there 1,3, 5, 20. Will it be determined by depth or by the amount of chapters over all? At the end of the day Friedman calls it.
I like to establish the story at least two chapters deep before publishing, and have ALL the potential "Chapter Twos" written as well - between four and six choices. Essentially, I'm writing several introductions which start the same way but then go in different directions. Then, one of my rules is that any submissions from the outside must be threads which continue off one of the "Chapter Two" options, not from the introduction itself. Any story requires three elements: setting, characters, and plot. The setting and the protagonist are established during the intro, but the plot is largely directed by that initial choice, and I like to exercise a degree of control over that. If this is going to be a story about a guy in college, I don't want a plot thread right at the start which enlists him in the Army. So, the Intro will provide a brief backstory for the protagonist, describe the college campus, narrate what the day has been like so far, and detail what's going on at the moment which has led to this moment of decision. I'll then write the chapters for which he goes to the library, heads over to the student center, checks out an off-campus party, or goes to see what his friend {first_name} is up to. That, I think, gives potential contributors a better idea of what kind of story it's trying to be than if it was just the first chapter. I'll also usually take one of those initial options and run at least three more chapters deep with it - this is partly to give an example of what kind of story it has the potential to be, but it also generates more reader interest. A new story that's just two short chapters deep feels like someone had an idea but wasn't even interested enough in it to explore it themselves; if the story's creator isn't more invested than that, why should I be? I'll also create an option off the Introduction for "MEET THE CHARACTERS IN THIS STORY". This helps to avoid the problem of mischaracterization by other writers; I can state at the beginning that Jenny is the slutty wannabe popular girl, while Annie is the nerdy girl with lesbian fantasies, and Samantha is the aloof cheerleader who secretly wants to be dominated. This is also an opportunity to provide pictures so that other writers get the descriptions right; it's helpful to know who's a blonde and who's a brunette. But that's just the way I roll; I wouldn't expect such stringent guidelines to become requirements, nor would I want them to. If a story is written with a short introduction which doesn't grab my interest, I'll just ignore it.
I'll admit that when I first published my first story I thought Private meant other people couldn't see it. So when it got approved and was available publicly I was surprised. Luckily it was an actual story and not blank. I originally thought I could work on something privately and then publish it. I can imagine some people playing around with the forms and trying out variables for the first time and then realizing they made a mistake.