The Arma III website has the announcement of Arma III: Zeus, a free DLC pack coming to Bohemia Interactive's military shooter sequel in Q2 of this year (thanks Gamer's Hell). Here's a reveal trailer, and here's a bit of the announcement:

Improvisation is the ultimate key to success in Arma 3 Zeus. Inspired by popular tabletop games such as 'Dungeons & Dragons', a limited number of players can assume the role of Game Master, and influence the multiplayer experience of those with boots on the ground. Watching the battlefield from a bird's-eye view, wielding an intuitive real-time editor, Zeus can create, manipulate or expand mission content to generate new stories and a flow of challenges. The result is incredibly dynamic, unscripted combat gameplay - and multiplayer sessions which are filled with unexpected, challenging, and creative events.

The Zeus multiplayer concept works across all familiar multiplayer game types, such as Team Deathmatch and Sector Control, where players can either work with or go up against Zeus. The most distinctive game type in Arma 3 Zeus, however, is ‘Zeus Game Master’. Here, Game Masters are entirely free to create objectives, spawn units, and steer players across Arma 3’s massive Altis and Stratis terrains.

On top of the diverse range of official Zeus scenarios that will be available, Arma 3 Zeus can also be implemented into player-created multiplayer scenarios.