|This article is about the the Imperial Guard manual. For other uses of Tactica, see Tactica (disambiguation).|
The Tactica Imperium is the most widespread manual employed by the Imperial Guard. It is not a single tome, however, and has no single author; instead it is a whole collection of documents, doctrines, manuals, and notes approved for inclusion by the Departmento Munitorum and the office of the Lord Commander Militant of the Imperial Guard. The collection of books comprising the Tactica is therefore constantly being updated, often at a different place, as the sheer size of the Imperium precludes any true standardization.
The Tactica's origins lie in the days of the Emperor's Great Crusade. In those times, vast forces were being raised quickly and it became evident that some standardization was needed to make them function as a whole. Any available texts were seized on and distributed to provide at least some guidance. Over time this initial collection expanded.
Now contained within the Tactica are treaties on construction of field fortifications, the correct evolutions of close order combat drill, the oaths of allegiance to be made by new recruits, and the statutes of military law. Many of these are adopted verbatim, although some are best viewed metaphorically. The tactical treatises in particular are subject to many different interpretations. Their value lies in provoking thought and, through it, understanding of the core principles so these can then be applied by a good commander as needed.
The Tactica is not meant to be taken too literally though. In war, circumstances change too quickly to refer every decision to a book. Its virtue is that it provides reference for new officers and there is always a chance that guidance can be found on a critical issue.
A collection of some passages of this book can be found here.