Board Thread:Questions and Answers/@comment-26121027-20170104233755/@comment-24045678-20170105021128

As far as I know, games like Warhammer: Mark of Chaos (Empire storyline is canon), Shadow of the Horned Rat and a few others except Warhammer Online are considered canon in the universe.

The key here is that Games Workshp puts alot of emphasis on sandbox in their games. Essentially, so long as it dosen't rewrite major lore and is SIMPLY set in the Warhammer universe, this wiki will allow it.