As per this discussion visual-novel is likely to be removed in the near future, since it's mostly a meta-tag. In the discussions contained therein, I suggested that we create a visual-novel-production tag for questions about how visual novels are produced, analogous to anime-production and manga-production. This comment got 2 upvotes and no responses, but I've now realized that it might be somewhat controversial based on earlier decisions.
After looking at the tag wiki for visual-novel, it says:
This could be interpreted as stating that visual novel production questions do not belong on Anime.SE at all, and should be asked on GameDev.SE instead Note, however, that tag wikis represent the viewpoint of at most 3 people, and are often wrong or out-of-date, so this should not be considered official policy. (This tag wiki is also somewhat out-of-date, as we are now allowing anime-style VNs which have not been adapted as anime/manga, contrary to the description, but there is little benefit in fixing it as the tag will be gone soon anyway.)
The final paragraph of my answer here also implies that questions related to the production of anime-style cartoons, games, etc. is off-topic, but doesn't say anything about visual novels specifically; visual novels were already within our scope before that post.
In any case, it seems this issue has not yet been settled decisively on meta. So, the question is, do we allow questions about production of visual novels? And, if so, what guidelines do they need to follow?
Note: We currently have one question which could be affected by this decision: https://anime.stackexchange.com/q/420/24, which at the moment is closed as Off-topic with +2/-2 votes. The discussions contained therein are also relevant to this discussion, though we should keep in mind that this occurred during private beta and our scope has changed substantially since then.