The Kasrkin are elite troops of the Imperial Guard and are dedicated to the security of the Fortress World of Cadia from which they hail. Because they are elite special forces troops drawn from the same world as the existing Cadian Shock Troops Regiments of the Imperial Guard, the Kasrkin are officially classified by the Departmento Munitorum as the type of Storm Troopers known as Grenadiers. Their name comes from the title of the fortress cities of Cadia, which are called "Kasrs" in the native Cadian dialect of Low Gothic. The Kasrkin are the elite of the already skilled Cadian planetary military forces and are chosen to serve in the Imperial Guard when they are still serving as Whiteshields (new recruits) in the Cadian Planetary Defence Forces. Their training is more than a match for that provided to the elite Imperial Storm Troopers (Kasrkin are the Cadian equivalent of the Storm Troopers) and they are utterly dedicated to the preservation of Cadia, whereas Imperial Storm Troopers are indoctrinated to provide for the defence of the entire Imperium of Man. Kasrkin soldiers are well-known amongst the Storm Trooper Regiments assigned to Cadia, and are renowned for their ability to remain cool under fire in combat situations where even many other veteran Cadian Guardsmen would break.
Kasrkin are highly trained in the use of numerous heavy weapons, and their Hellguns and Hotshot Lasguns are much more powerful versions of the normal Lasgun used by regular Guardsmen. They wear Carapace Armor, which deflects and absorbs incoming projectiles far better than standard Guardsmen's armor. They are also given minor biological modifications to allow them to move quickly despite their heavier gear. They have an ethos of duty and honour that is impressive for members of the Imperial Guard, who are usually far more interested simply in staying alive. Whereas the standard Storm Trooper is looked down upon by many different regiments of Imperial Guardsmen for their elite status, the Kasrkin are looked upon with great favour among the standard regiments of Cadian Shock Troops. They are the ultimate warriors of the Imperial Guard who fought against the Forces of Chaos, and they led the charge in the defence of Cadia from the Chaotic forces of Abaddon's 13th Black Crusade in 999.M41 that is currently still occupying much of the Fortress World's surface. To be a Kasrkin is to hold a position of honour, and all Cadians recognise this truth and the role they play in defending their world.
- Storm Trooper Carapace Armour - Carapace Armour is generally a sign of status and is mostly worn by Imperial officers and agents. Made from moulded plates of armaplas, ceramite, or other strong, light but highly resistant materials, it can cover the entire body or just selected regions of the body depending on the desired level of protection. Kasrkin, for example, wear full-body suits of Carapace Armour, including a helmet, while most Imperial Guard soldiers are lucky to gain access to just a simple chestplate of Carapace Armour to wear over more comfortable mesh or flakweave suits. Some bodysuits have slots designed for simple carapace plates to be inserted in, so that the overall suits can be rapidly configured for as much or as little protection as desired. Damaged plates can in this way be more easily replaced without requiring the purchase of an entire new suit.
- Cadian Imperial Guard Fatigues - Kasrkin generally wear the common battledress uniform or fatigues that are standard to their attached regiment beneath their Carapace Armour.
- Micro-Bead - A micro-bead or comm-bead is a short-range radio wave communication device worn in the ear, good for communications out to about one kilometre (depending on weather conditions and the intervening terrain). Each fits discretely in the ear, with higher craftsmanship models nearly undetectable in casual inspection.
- Respirator - A simple breathing mask that covers the nose and mouth or entire face, these offer much better protection than filtration plugs and are used by Storm Troopers in toxic environments or during attacks by chemical or even biological weapons.
- Hotshot Lasgun (Lucius Pattern) - Sometimes also known as Hellguns, "hot-shot" weapons are almost exclusively used by high-ranking Imperial officers and elite forces who favour the higher power provided by these weapons over the higher rate of fire but poorer penetration power of the Imperial Guard's standard-issue laser weapons. While Hellguns are rarely seen employed in the Imperial Guard outside of the elite Storm Trooper units, Hellpistols can be seen in use among many members of the Guard's officer corps and among agents of the Inquisition where their greater power often means the difference between life and death.
- 4 Charge Packs for Hotshot Lasgun - Charge packs are powerful batteries used almost exclusively by Imperial laser weapons. The cost of a charge pack varies depending on the class of the weapon. In all cases, it provides shots equal to the weapon's full clip value.
- Combat Knife - This one-handed melee implement is the ubiquitous back-up weapon for warriors all across the Imperium, be they lowly hive scum or the elite soldiers of a Planetary Governor. Some, such as the Catachan Fighting Knife, are designed for a specific purpose, whilst others are more generic in nature.
- Imperial Infantryman's Uplifting Primer - A standard-issue Imperial text that covers a vast variety of topics, this book is possessed by all members of the Imperial Guard as part of their standard-issue equipment. The Primer is a basic guide that details everything a Guardsman needs to know: principles and regulations of the Imperial Guard, issued arms, attire, apparatus, and equipment, basic battlefield policy and Imperial Guard organisation and structure, elementary battlefield medical instructions, and a detailed guide on the foes of the Imperium. No Guardsman should ever be found without possession of a copy of the Uplifting Primer, for the punishment is severe. The Primer is a basic guide to life in the Imperial Guard and the tactics employed by its regiments. Even elite Imperial troops like Kasrkin often times still rely on its advice.
- Codex: Imperial Guard (5th Edition)
- Codex: Imperial Guard (4th Edition)
- Gunheads (Novel), by Steven Parker