Unvanquished is an open-source FPS game featuring team-based strategy and RTS elements, pitting humans against aliens in a futuristic setting.
https://forums.unvanquished.net/
So what is the current licensing status for the wiki?
I want to add some pages but I don't want to contribute to non-free contents, so as long as every page is CC BY-NC-SA, I cannot make the changes I want.
Possible compromise: all pages have the old license until they have been edited, upon which they receive the new license.
Is that fair? Does that work?
I'm not sure it would be legal unless all people who made significant contributions agree to the new license.
We can make CC BY-Sa the default license and add a banner which explains the situations and says that page is CC BY-NC-SA for the moment and if the authors agree or the page gets re-written, it can be removed.
I would be OK with this, is everyone else OK with this?
Can we assume everyone is OK?
I'm just going to ask Viech on this and then I'll render my final decision on the matter.
I'm OK with this. Contributors could be asked to give their respective OK on the license change on the discussion page.
OK. With that being said, the compromise is approved. Go ahead, Melanosuchus.
So, what it the status currently? I made some wiki edition recently and I really don't like writing -nc stuff. 
I give permission to relicense everything I write (past, present, and future) in the wiki if it's to remove -nc clause.
Do we have a list of all wiki contributors? Can we relicense each page for which we know all the contributors are ok to remove the -nd clause?
If I read correctly: people who said they are OK to remove NC clause on their wiki contributions:
@Veyrdite
@lamefun
@Viech
@Melanosuchus
@Calinou
@illwieckz
@kharnov
That probably matches a big part of the content. All pages here.
We can probably add a global sentence saying “Content is available under Creative Commons Attribution Share Alike unless otherwise noted.” and run a script that looks for pages that were modified by someone else than people listed above and add a sentence in the page saying “This page is under CC BY-ND-SA because <insert name here> was not reached to relicense it. By contributing to this page you give the permission to relicense to CC BY-SA if one day the former contributor(s) guys give(s) that permission for their own contribution”.