Heads up! As of the new update released today, the season pass has been retired and all DLC will now be free!
They are also offering free trial weekends for PC, PS4 and Xbox One
Details from the link:
All of the Multiplayer DLC Unlocked for All
First, we’ve retired the DOOM season pass and are making all of the multiplayer DLC content available to all players. That’s three multiplayer DLC packs, which include nine of our best maps, three additional guns, three additional playable demons, new equipment, armor sets and more. That’s on top of the modes and features, like bot support, that players have been enjoying since late last year.
Free Weekends
If you’re someone who just hasn’t tried DOOM yet, we’re giving you the ultimate opportunity to try out one of the most talked about games of 2016. Starting at 12:00 pm ET on Thursday, July 20, on Xbox One, 1pm ET on Thursday, July 20 on PC, and 12:00 pm ET on Thursday, July 27 on PlayStation 4, you can try DOOM for free. Blast hordes of demons in the first two levels of DOOM’s critically acclaimed campaign, then ratchet up the intensity by going for a high-score in Arcade Mode. Plus, you’ll also have unlimited access to DOOM’s multiplayer and SnapMap modes for the duration of the weekend. If you choose to purchase during the free weekend, all of your progress in campaign and multiplayer is saved and you’ll continue right from where you left off.