Strange, they work from my phone but not from my desktop.
Instead of showing me archive.wizards.com, it redirects me to dnd.wizards.com with a 404 "this article might be outdated or moved" message. I wonder if I have an extension or something that's causing that.
I use Chrome Mobile on my phone, and regular Chrome on my desktop.
Edit: Yup, that's what it is. On my desktop I use an extension to force HTTPS everywhere, which is what's causing the redirect.