When a Student tries to navigate to a Discussion that has this setting enabled, they will be taken first to the Create a new Discussion Post dialog. A Student will have the option to submit a new Post or even save this Post as a Draft, but will be unable to view or reply to any Posts that have been made by their peers until a Post has been submitted.
Teachers can enable this setting for new Discussions as well as existing ones.
You can even add this feature to a Discussion that you have already created. This can be helpful when the Discussion has been created as a copy of an existing class that didn't use this option.
Here's what you can do: