Recently it came to my attention that there are per-site configuration settings that allow us to create some extremely minor barriers to answering questions when more than n answers already exist. This is currently implemented on the site but the threshold for tripping it is set at 30 answers.
The difference is that, instead of an answer field, there's a button that reads "Answer this question" which, when clicked, creates a popup with the following text:
This question has more than {x} answers already.
Did you read through all the existing answers first to make sure your answer will be contributing something new?
Also, please note that you can click the edit link on any of these answers to improve them.
This doesn't prevent answers, per se, but it does ask users to be cognizant of the existing answers before posting their own.
Should we request this limit to be lowered, and to what?
As a note, questions are automatically flagged by the system when a question receives ten answers within seven days. We largely ignore these flags because there's not much for us to do about them, considering the vast quantity of answers we get here. I'm also interested in changing this auto flag, which is apparently also configurable. This doesn't affect the users as the only people who see it are mods but we need to request it on meta to have it changed.
I think that, since the system sees fit to flag at 10 answers, we might consider something lower than that for the "answer this question" button - perhaps something around seven.