The main game currently has 13 missions, divided into 3 acts, each with a final Boss. There are 13 missions intentionally, as 13 is the sacred number of the Horned Rat, the Skaven god. After defeating the Boss of each act, you can progress to the Final Mission. Missions can be played on four Difficulties, five with the DLC Winds of Magic.
A repeatable Prologue mission is played automatically the first time you start up the game after which you are taken to Taal's Horn Keep, the home base of our Heroes.
The first DLC, Shadows over Bögenhafen, adds two missions. The second DLC, Back to Ubersreik, adds three more along with one hidden. The third DLC, Winds of Magic, adds one new mission. The free update,The Curse of Drachenfels, adds three more.
Shadows over Bögenhafen
Back to Ubersreik
Winds of Magic
The Curse of Drachenfels