User blog comment:Jykale/Doom + The Elder Scrolls= shared universe?/@comment-1496755-20160923131405

Interesting theory, though I suppose the designers would prefer to keep the game universes separate. Doom could easily mix with Quake and Wolf, but TES is a possibility too.

I have a theory of my own too - that all the Doom games connect together, creating Ages. The First Age is the classic Doom games (Ultimate - Final), the Second Age is Doom 64, and the Third Age - Doom 3 and Resurrection of Evil. Obviously, Doom 2016 is the Fourth Age...