Earlier this month, Valve announced that it would be adding a co-op campaign to the popular free-to-play multiplayer online battle arena. Act I is now available.
Siltbreaker is a three-part adventure for four players that will deliver special rewards to player who survive the conflict between the evils of the Dark Reef and the heroic Conclave of the Brine.
Anyone who has a Battle Pass will be able to take on these lethal terrors in Dota 2’s first cooperative campaign, and each playthrough will give players a chance to earn in-game
Artifacts, which are mythic objects of power that can be equipped and used during the entire Battle Pass season.
[Source: Dota 2 Blog]