Editing Nobledark Imperium Imperial Forces (section)

===Doctrines of the Imperial Guard===
In addition to the famed Cadian Doctrine, many regiments have also developed their own unique methods of fighting which have then spread throughout the Imperium. While this is hardly an exhaustive list, it provides a decent look into the sheer diversity of the Guard.

====Infiltration Doctrine====

Infiltration doctrine is a light infantry doctrine focused on stealth and mobility. It omits vehicles and heavy artillery from the TO&E almost entirely, relying on crew-served weapons for heavy firepower, which can be dismantled and carried by an infantry squad. On the offence, infiltration regiments use their stealth and lightweight equipment to close with enemy formations undetected and from unexpected directions; once all elements are in position, they launch an overwhelming surprise attack from close range, using their crew-served weapons and snipers to suppress the enemy and ensure they cannot mount an organized defence. On the defense, they use the same qualities for hit-and-run raids, whittling down the enemy and melting away into the night when the enemy tries to bring their firepower to bear. 

Infiltration regiments are usually equipped with specialized equipment such as camo-cloaks and night-vision goggles, but these are less important than how the regiment is trained. The nature of their operations require that officers and NCOs be trained to a higher standard of independence than normal, as units as small as squads will often be trusted to maneuver individually in support of the overall objective. This usually cultivates a sense of being elite; combined with the looser chains of command infiltration regiments usually operate with, other regiments usually consider them insubordinate and undisciplined. 

In combat, infiltration regiments are used to secure and move through terrain that mechanized regiments cannot. They are also used in combined-arms strategies to scout out enemy positions, assassinate officers, and destroy enemy strongpoints in advance of the main armored thrust. Infiltration regiments also maintain their effectiveness easier in the face of enemy air and orbital superiority thanks to their ability to fight while remaining hidden and dispersed. Finally, infiltration doctrines are popular among PDF forces incapable of maintaining large mechanized armies. As powerful as they are within their specialty, however, their lack of vehicles and artillery makes them perform poorly outside of it.

====Armageddon Doctrine====

Armageddon doctrine is a maneuver- and terrain-focused mechanized infantry doctrine. Developed by the Steel Legion in their endless battles against the Orks, Armageddon doctrine TO&E is extremely vehicle-heavy, with sufficient Chimeras to carry the entire regiment, strong organic artillery support, and at least a modest tank detachment. Mechanized scout detachments — Salamanders, Sentinels, and bikes (preferably jet-bikes) — are common, but can also be delegated to other specialized regiments. The Steel Legion itself uses the Outriders for this purpose, but other regiments have alternative solutions. Likewise, organic combat engineering support is common, as are air defense vehicles; Hydras in particular are valued for their ability to sweep aside Ork hordes in addition to aircraft. Soldiers are heavily armored in carapace.

In combat, Armageddon doctrine is often described as 'operationally offensive, tactically defensive'. Using the scout detachment to survey the terrain and enemy dispositions, the regiment seeks to seize vital terrain features before the enemy and fortify it, forcing the enemy to assault a fortified position on a terrain of the Imperium's choosing. To this end, Armageddon-style regiments usually carry copious amounts of barbed wire, mines, and other defensive implements; vehicles are equipped with dozer blades to dig out entrenchments. This is where the engineering detachment comes in. The scout detachment, if present, harasses the enemy on its approach, although this is not a vital component of the doctrine.

At the level of individual squads, Armageddon doctrine emphasizes close cooperation between infantry and armor; full mechanization means each squad has a Chimera, which they are responsible for defending from threats and vice versa. 

Few worlds adopt the Armageddon doctrine in full. Although many other mechanized infantry forces adopt its emphasis on mobility, terrain, and forcing of the enemy to attack fortified positions, few worlds can afford to equip their regiments with the same weight of metal as Armageddon and thus do not adopt the full TO&E. In addition, the emergence of the Brain Boy caste has thrown the doctrine into flux; with the Orks no longer throwing themselves as eagerly into near-suicidal charges, the strategy has lost some of its effectiveness. Although the core of the strategy remains sound, the arguments at Steel Legion HQ about how to adapt to a changing galaxy continue long into the night.

====Fast Attack Doctrine====

A light-armor and occasionally bio-cavalry doctrine focusing on the use of speed and maneuverability as weapons. 

There is no standard TO&E for Fast Attack regiments, due to the wide variance in equipment used. Salamander scout tanks, Sentinels, motor- and jet-bikes, a thousand varieties of armored car and riding beasts. A very few forge-worlds even have super-heavy fast-attack companies, equipping tanks as heavy as Baneblades with antigrav units to allow them to keep up with lighter forces. 

Whatever the equipment, all Fast Attack units operate similarly: using overwhelming speed to strike at an enemy's weak points before an effective response can be mustered. The 'classic' pattern of attack is to punch straight through the enemy line and rampage through the rear areas, but that is hardly the only tactical possibility. Outflanking maneuvers, hit-and-run raids — speed opens many possibilities. 

Fast Attack regiments are usually deployed as part of combined arms strategies, scouting for slower units or exploiting breakthroughs created by heavier ones. On their own, while fast and generally well-armed, they are also more fragile than a true tank unit and lack staying power. This varies, of course; the dynamics of a horse cavalry unit differ from Sentinels and Salamanders, which in turn differ from jet-bikes. But the general principle holds; as with so many other things in the Imperium, there is strength in diversity.

Fast Attack units, like Infiltration units, are often popular among PDF forces which cannot sustain heavy tank formations but can build light tanks and armored cars or breed horses, which contributes to the wide variance of regiments following the doctrine.