I can't believe a thread for this hasn't been made yet because I know a lot of TPU members play it. Steam Wikipedia Wikia Overkill Software Skill Tree Calculator/Planner CRIMEFEST - October 18, 2014 Joining the Payday 2 Official Group unlocks four weapons, three masks, and a bunch of weapon mods. Additionally, the more sign ups they get by October 18, the more rewards they will make available to everyone in the community. I don't think you even need the game to join. Official announcement for this event here.