New with the Shadows of Hammerhal is the gamemaster. There has been a lot of interest in this, so lets take a look at what the Warhammer Community is saying about it.
via Warhammer Community
https://www.warhammer-community.com/2017/02/22/closer-look-the-gamemaster/
One of the Gamemaster’s chief jobs is to control the adversaries during the game. This is done with a behaviour chart, as with Warhammer Quest: Silver Tower, but for narrative or malicious reasons (depending on temperament) the Gamemaster can choose to override the chart if they feel inclined. They also have the ability to use models to call for reinforcements and are responsible for placing these new adversaries when they appear. They also get their pick of exotic adversaries, when that is called for (more on that tomorrow).
The Gamemaster’s other main role is to guide the heroes through the district of Cinderfall in the city of Hammerhal above. In doing so, they variously play the role of merchant, pit fighter, priest, fortune teller, drunkard and many more*.