The rules for fielding Astromancers, Crane Gun Teams, Iron Hail Gunners, and Peasant Levy in your games of Warhammer: The Old World can be found in Arcane Journal: The Breaching of the Great Bastion. This book also contains in-depth lore and background on the Land of Dragons, including how the inhabitants of Grand Cathay band together to defend their home from invaders. Speaking of which, there are rules to fight the legendary Battle of Nan-Li on the tabletop – can you hold the line against the Warriors of Chaos?
