The Old World is a dangerous place. With the Empire fractured within and threatened by enemies without, it is only wise to learn the skills of a soldier, or to employ those who already have. Some may say that to live by the sword is to die by the sword, and there is truth to this. But in the wilds of the Empire, to refuse to live by the sword is to die by the sword even sooner. Up in Arms provides options and guidance for Warhammer Fantasy Roleplay Characters who follow warrior careers. It focuses on abilities that players and GMs can make use of to add variety and expertise to the fighting folk of the Old World. This 144 page book contains: A discussion of the Cult of Myrmidia, giving the most comprehensive guide yet published to the beliefs and practices of those who worship the Goddess of Strategy. Soldiers of all Stripes, detailing the experience of the rank-and-file members of the Empire’s glorious state troops, and providing new careers such as the handgunner, halberdier, and greatsword. A history of the role of mercenaries in the wars of the Old World, including background and rules to support playing Tilean Characters and other dogs of war. A guide to the renowned knightly orders of the Empire, with options for joining secular orders, templar chapters, or going it alone as a freelance knight. An expanded list of weapons and armour, from basic arms such as swords and axes, to exotic specialised equipment such as weighted nets and pavises. Rules for taking cover within vehicles and buildings — and counterpart rules for blowing vehicles and buildings up with devastating artillery. Detail on the employment of hireling NPCs, including a system for generating individual quirks and work ethics. Optional and additional rules covering new Endeavours, alternative approaches to Critical Injury, mounted combat, uses of Advantage, Pursuits, and Talents.