The Dark Ages talks about why the game won't include a multiplayer mode like the past few titles in the series.

One thing, in particular, highlighted in the first round of previews - is the fact this game is a "strictly campaign" affair. In other words - don't expect multiplayer to feature. Here's exactly what Marty Stratton had to say about this ( via Eurogamer ):

Takes you closer to the games, movies and TV you love Try a single issue or save on a subscription Issues delivered straight to your door or device Doom: The Dark Ages pre-orders are officially live,