Are *all* list questions off-topic?

Question

"List questions" are generally off-topic on Stack Exchange sites, and Science Fiction & Fantasy in particular, because they tend to be open-ended, generate debate, have some level of personal preference, and not meet the criteria of being "answerable". But there are plenty of list questions on this site that do have a single, demonstrably correct answer that just happens to be a finite list of items.

Just today, on the front page, there are a bunch of questions with list answers and our treatment of them is very inconsistent:

• https://scifi.stackexchange.com/questions/31626/x-files-references-in-fringe
• https://scifi.stackexchange.com/questions/31625/twin-peaks-references-in-the-x-files
• Are there any spells that a wizard/witch can cast without a wand in the Harry Potter universe?
• Other than Morgoth, were any of the Valar ever susceptible to physical injury?
• Who are all the characters to have touched The One Ring?

All of those questions have a list-based answer. Some of them are being rapidly downvoted and VTC'd, while the Harry Potter one has 33 upvotes and an accepted answer.

Note that, in every case, we have all of the information needed to build the list, the criteria is objective, and since the works are completed, the list will never change. That addresses almost every complaint people have about list questions.

So, if list-questions are off-topic, where's the line?

Answer 1

The ban on list questions is mainly on open-ended infinite list questions. This is touched on in the site FAQ:

Please note the following types of questions are off-topic here:

...

• Questions calling for a list of works, authors, …: What are all the books that have X? Who wrote about topic Y?

It's not reasonable to ask a question on a Q&A site that requires knowledge of all works that ever existed, and then request a massive list of the works that contain one specific element. This sort of question lacks a single, finite answer. In practice these questions accumulate a steady flow of "me, too" answers where people add a few examples in a new answer.

However, finite and well-scoped list questions are allowed here. There's a question asking for a list of all of Doctor Who's Doctors, for example. A mere 13 Doctors exist (within the main BBC show, in both incarnations), which can be reasonably included in one, canonical answer. Similarly, a question asks about all of Star Trek's Enterprises. There's a reasonable, limited number of those as well.

The reason half the questions linked in your question are getting downvotes is likely due to their low quality. They show a lack of research, and come off as 'do this time-consuming research for me!' types of questions. We'll see how the community reacts to them, and what sorts of answers they receive.

In contrast, the high-upvoted questions show some expertise. The details in the question indicate the asker has a familiarity with the works, and is seeking something odd, rare, or not-obviously-stated in those works.