Astra Militarum - Deployment and Training: In those instances where a threat to the Imperium cannot be repulsed by local defence forces and naval assets, the Departmento Munitorum will sanction immediate deployment of the Imperial Guard. Such a response will be guided by the wisdom imparted in the strategic parables of the Munitorum. This threat response pattern has served the Imperium well for thousands of standard years.Initial forces will be drawn from localised assets deemed sufficient for the task at hand. This includes any Guardsmen already mobilised within response range, along with regiments raised from neighbouring worlds. Such forces can be disparate in nature, requiring officers to prove themselves adept at working with whatever materiel is at hand. Should a threat escalate, or prove greater than initial response forces can handle, the Munitorum will expand their designated conflict zone, drawing down relentless waves of reinforcements to crash upon the foe until it is entirely ground to dust. In this way even the onrushing fury of an Ork WAAAGH! can be brought to a grinding halt, or the nimble Eldar drowned in manpower and ordnance.Regiments en route to their designated warzone usually possess some previous military experience, whether culturally inherited or earned through campaigns already fought in the Emperor's name. While aboard their troop-ships these regiments will be further trained to deal with the specifics of the war into which they are being sent. Whether this is learning to recognise and combat particularly inhuman foes, use of environment-specific equipment, or acclimatisation to peculiarities of the destination world, such orientation can be vital. Imperial Guard regiments from Feral Worlds, for example, would be rendered catatonic if unprepared for the immensity of the standard Imperial hive city.On deployment, Imperial Guard forces operate according to the tenets of the Tactica Imperium, stringently enforced by their rigid chains of command. Regiments complement each other's strengths and weaknesses, ensuring that the army as a whole is greater than the sum of its parts. When facing especially ferocious or peculiar enemies, such as daemons spilling from a Warp rent or the horror of a Tyranid swarm, this standardised method of making war can encounter costly snags. Yet with the constant flow of new manpower enjoyed by high command, individual engagements with casualty rates as high as one hundred percent can be considered rousingly successful, providing the fallen first achieve their allotted tasks or highlight some strategic weakness in the foe.When an army is assembled, regiments are drawn from many different planets, resulting in a conglomeration of uniforms and combat skills rather than a single homogenous force. Bio-screened techno-troopers fight side by side with primitive barbarians and noble-born soldiers rub shoulders with the lowliest hive gang fighters. When WAAAGH! Grax invaded the Ryza System, all planets within ten light years were ordered to recruit and raise at least an additional fifty regiments as a primary reaction to counter the Ork invasion. Should the Imperium's response not prove to be decisive in crushing an enemy then the sphere around the conflict zone is increased in ever-larger increments, as reinforcements are drawn from further away and more regiments are raised to replace the losses. This ponderous process repeats itself until the enemy is ground down and destroyed, the massed forces of the Astra Militarum slowly pounding at the foe until eventually the hammer blow is delivered and all resistance is completely and utterly shattered. In this way, the harder a foe strikes at the Imperium, the greater its response will be.Many of the newly raised regiments inducted into the Astra Militarum will already have some modicum of fighting experience. This may have taken the form of formal military instruction or simply be the result of the harsh conditions in which they live. Only the strongest survive the gang wars of the Hive Worlds, the tribal conflicts of medieval Feudal Worlds or the carnivorous predators that stalk the Death Worlds. In any case, during the long voyage between their homeworld and the regiment's destination, the newly inducted Guardsmen will receive intensive training that tempers the natural fighting skills of their many disparate cultures and forges them into soldiers worthy of the Astra Militarum. They are trained in the use of specialised weaponry and vehicles and receive proper indoctrination into the Imperial Cult. Officers are tutored in the broader aspects of the Tactica Imperium, all the while being judged under the vigilant gaze of the Officio Prefectus. The regiment will be drilled for many solar weeks before their trial by fire in the crucible of war. The training is also intended to adapt and, where necessary, re-educate the new recruits for the inevitable shock of fighting on foreign worlds. It is unlikely that a Guardsman from the monolithic spires of a hive city has ever seen the open sky, whilst those from a backwater Agri-World will never have seen the towering might of a mountain-sized basilica sanctum or set foot inside the twisting labyrinth of a sprawling factorum-city.Should a regiment survive a campaign, it is unlikely that it will return to its homeworld, moving instead from one war zone to another. As casualties reduce the overall strength of fighting forces, regiments are often amalgamated together so that, united, they can continue to wage the Emperor's wars. Where possible, two half-strength regiments from the same Militarum Regimentum will combine, but it is not uncommon for two disparate cultures to find themselves brothers-in-arms. Many commanders declare that the reduced efficiency of these combined regiments makes them barely worth their rations, infighting and mistrust hampering their battlefield effectiveness. Other commanders are interested only in the number of men-at-arms that can be fielded, their successful integration as fighting units a secondary concern. A handful of particularly canny officers prefer to lead combined regiments, as they can harness the diverse skill sets and ingrained competitiveness of their soldiers.If a regiment has been so badly mauled that it is considered a waste of time and resources to combine it with other Imperial forces, they may be assigned garrison duties on a nearby world, usually the very same planet they have been fighting over. The safety of the world and its population becomes the duty of the regiment's remnants. The garrisoning of such worlds is vital. After a brutal war in which the local defence forces are inevitably decimated and the planetary government left in tatters, the small Astra Militarum contingent may be the only loyal force left to impose law and maintain control for many solar decades. In rare circumstances, a regiment may be granted custodianship over a world as a reward. The officers of such forces inevitably become wealthy and powerful figures in the society they maintain watch over, forming the new noble and ruling classes.