The question regarding how they created the hole in Robert Downey Jr's chest was recently migrated to the Movies stack exchange. I agree that it is probably a better fit there, but as of last night, I saw that it had received 4 close votes for being "off-topic".
As Xantec pointed out the FAQ notes that questions regarding
Behind-the-scenes and fandom information
Clara Onager mentioned that it was off-topic because
This should be a movies and tv question as it primarily relates to a special effect technique and only secondarily to scifi.
But the same could be argued about a lot of behind-the-scenes questions.
Take these questions, for example:
- How did Weird Al Predict "The Phantom Menace"? This question is really about how Weird Al may have come across massive spoilers or leaked information (in truth, he didn't - it was all based on rumors).
- Why are the Bene Gesserit tonsured/bald in the movie? This question is really about why a director made a choice.
- Why is Snarl not in Transformers: The Movie This question is really about why writers left someone out of the script.
- What is the reason John Williams did not compose more for the Harry Potter Movies? This isn't a question about sci-fi/fantasy at all; It's about why a composer did not get/take a job.
- How was E.T character created in the movie E.T -The Extra Terrestrial? Awfully similar to the Iron Man question - asking about how effects were created FOR a sci-fi/fantasy movie.
- Why did Peter Allan Fields leave “Deep Space Nine”? This is about why a producer left a show.
- How were the DRDs on Moya operated? This is about how special effects units were operated.
I don't actually think that any of the above questions are off-topic. They may skirt that same line that the Iron Man question did, but they all fall into "behind the scenes and fandom information" regarding a sci-fi/fantasy work.
So, what sort of guidelines should we adhere to for defining what is, or is not "on-topic" in regards to "behind the scenes" questions?