Space Marines

Foremost amongst the defenders of mankind are the Space Marines of the Adeptus Astartes, the greatest of the God-Emperor's soldiers. They are barely human at all, but superhuman; having been made superior in all respects to a normal man by a harsh regime of genetic modification, psycho-conditioning and rigorous training. Space Marines are untouched by plague and can suffer wounds that would kill a lesser being several times over, and live to fight again. Clad in power armour and wielding the most potent weapons known to man, the Space Marines are terrifying foes and their devotion to the Emperor and the Imperium of Man is unbreakable. They are the Angels of Death, and they shall know no fear.

Potential Space Marines are recruited from the worlds where a Chapter has established its fortress monastery, although some are known to recruit from a collection of worlds. Recruiting methods vary from chapter to chapter. Some select their cadets from feral tribes roaming the surface of inhospitable worlds, while others draw upon eager volunteers who have been groomed from birth to become an Astartes. Still others watch and kidnap potential warriors, turning them into Astartes whether they will it or not. Whatever the method, all Space Marine chapters will only accept those who successfully pass the grueling initiation trials and prove themselves worthy of becoming a Space Marine.

Regardless of how a man becomes a Space Marine is irrelevant: once his body has been forged into that of a superhuman Astartes, he must forever stand aside from the people to whom he was once kin. Once a man becomes a Space Marine, he is no longer mortal; his heritage is that of the Emperor, and a spark of the same majesty flows in his veins.

Gene-seed
The Gene-seed of an Adeptus Astartes Space Marine is the foreign genetic material responsible for most of his physical changes. The gene-seed was cultivated from the DNA of the Emperor's 20 sons (each son being the Primarch of one of 20 Legions), and is a rare and precious resource for the Space Marines of death. The technology to create new gene-seed has long been forgotten, therefore it must be cultivated from dead/dying warriors and returned to the chapter allowing the creation of new astartes from raw recruits. It is the essence of the Chapter and with it carries each Marine's characteristics; mental, physical, spiritual, martial, and fraternal.

Gene-seed is vulnerable to mutations over time, which can manifest in various ways. In addition there are a various flaws which have developed in the gene-seed, the majority of which derive from particularities of each Primarch hence the flaws in the Blood Angels' gene-seed (specifically the Black Rage and Red Thirst), the "Curse of Wulfen" for the Space Wolves or the increasing rate of mutation within the Soul Drinkers Chapter.

It must also be noted that the present numerous Chapters are more numerous than the original 20 legions, excluding those whom are no longer recorded, the original legions have produced numerous chapters who share traits with their father-chapter.

During recruitment, some recruits may not survive the initial rigors of training and later medical treatments one must undergo to become a full-fledged Brother-Marine. First and foremost, a potential recruit must be male, as the gene-seed and zygote are synchronized to male hormones. The three following requirements also apply:


 * Recruits must be adolescents or very young adults, as the implants must be able to coordinate with natural growth hormones to stimulate various physiological features of a Space Marine. In specific terms, the recruit must be about 10-16 Earth standard years.


 * Much like a blood transfusion, there must be compatibility between the recruit and the implants; otherwise organ failure may result, causing the recruit to die or simply degenerate into a state of madness.


 * The mental state of a potential Marine must also be susceptible to the various training and psycho-conditioning regimes of the Chapter, and cannot be tainted by the Powers of Chaos.

These three main criteria bar all except a minuscule percentage of people within the Imperium of Man from becoming Space Marines. If all tests prove successful, the potential marine becomes a Neophyte or scout, depending on the chapters organization. The recruit is then taken to live at the chapter's fortress-monastery where he is instructed in the ways of battle and taught the values and history of the chapter. At this stage implantation, psycho-conditioning, and physical training begin. Each step in this stage has its own dangers, ensuring that only the truly worthy become Space Marines. After several years of training, conditioning, and surgeries the Neophyte becomes a Space Marine, undertakes his Rites of Fire, and becomes a fully-fledged Battle-Brother.

Implantation
Nineteen organs are implanted in a Neophyte to further bolster his combat and survival ability should he live to become a Brother-Marine. Each implant has a high margin of catastrophic failure and so only a small number of Neophytes live to become Initiates. Many chapters have lost the knowledge needed to create some of these implants, and therefore, must ensure these are recovered from dead Brother-Marines. Amongst the crucial implants are the Black Carapace and the Progenoid Glands, without which, a chapter would die out fairly quickly.


 * Secondary Heart - This is the first and least difficult implant to install. The Secondary Heart increases blood supply and pumping capacity and is capable of taking over entirely should the primary heart fail. It may also pump steriod into the 1st heart to give the marine an extra "rush" in the battlefield.


 * Ossmudula - This implant strengthens the skeleton of a Space Marine by inducing the bones to absorb a ceramic-based substance administered in a Marine's diet. Within two years after the surgery, the Marine's skeleton will be larger and exponentially stronger; and the rib cage will be fused into a solid bone plate.


 * Biscopea - Implanted into the chest cavity, this implant massively bolsters muscle development and density throughout the Marine's body. This is commonly implanted at the same time as the Ossmodula.


 * Haemastamen - Implanted into a main blood vessel, the Haemastamen alters the Marine's blood composition to carry oxygen and nutrients more efficiently.


 * Larraman's Organ - This organ manufactures Larraman Cells. These serve the purpose of platelets, but act faster and more effectively. When a Marine is wounded, Larraman Cells are released, attached to leukocytes. At the site of the injury, they form scar tissue in a matter of seconds, effectively preventing massive blood loss and infection.


 * Catalepsean Node - Implanted into the back of the brain, this implant allows a marine to not sleep, instead entering an almost comatose trance where they "recharge". It also allows the resting of half the brain while the other remains alert, thus removing the need for total sleep. The longest known record of any space marine going without rest while on active combat duty is 319 hours by a member of the Dark Angels.


 * Preomnor - The Preomnor is a decontamination chamber inside the chest cavity. It chemically analyzes ingested materials and neutralizes toxins. The Preomnor enables the Marine to eat normally inedible substances and resist poisons.


 * Omophagea - Implanted into the spinal cord, this organ is designed to absorb information and DNA related to experience or memory. This enables the Marine to gain information, in a survival or tactical sense, simply by eating an animal indigenous to an alien world.


 * Multi-lung - The multi-lung is a third lung, able to absorb oxygen from environments poor in oxygen. Breathing is accomplished through a sphincter in the trachea, allowing all three lungs to be used at full capacity. In toxic environments, a similar muscle closes off the normal lungs, thus oxygen is absorbed exclusively by the multi-lung which filters out poisonous elements.


 * Occulobe - Essentially, this organ enhances a Marine's eyesight, granting him exceptional vision and the ability to see normally in low-light environment.


 * Lyman's Ear - This implant renders a Marine immune to dizziness and nausea(seeCochlea), and enables a Marine to consciously filter out "white noise".


 * Sus-an Membrane - This implant allows a Marine to enter a catatonic or "suspended animation" state. It can allow a mortally wounded Space Marine to survive his injuries, and bring the metabolism to a standstill. The longest recorded period of this state was with Brother Silas Err of the Dark Angels for 567 years.


 * Melanochrome - Linked to pigment cells in skin, this allows the Marine's skin to shield him from dangerous levels of radiation and heat.


 * Oolitic Kidney - This organ works in conjunction with the Preomnor, filtering blood to remove toxins.


 * Neuroglottis - This organ allows a Marine to assess a wide variety of things simply by taste. From poisons to chemicals to animals, a Marine can even track his quarry by taste alone.


 * Mucranoid - Altering sweat glands, this organ causes the secretion an oily substance that coats the skin when necessary, protecting it from extreme temperatures and to some extent, vacuum environments.


 * Betcher's Gland - Implanted into multiple locations inside a Marine's mouth, these glands transform a Marine's saliva into corrosive, blinding acid when triggered. A Marine trapped behind iron bars would be able to chew his way out given a few hours.


 * Progenoid Glands - Implanted into both the neck and chest cavity, these serve to collect and cultivate the gene-seed from a Space Marine's body, and to safeguard it for the continuity of a Chapter. The neck gland is removed upon 5 years, and the chest gland upon 10 years; both are then used to create new Space Marines.


 * The Black Carapace - The last and possibly most important of all implants, this neuroreactive material is implanted directly under the skin in the chest area. Invasive fibre bundles then grow inward and interlink with the Marine's own nervous system. Points pre-cut into the Carapace are effectively connection points, allowing a Marine to directly interface with his Power Armour.

Scout Armor
This type of armour is usually only worn by Scouts. Given that their Black Carapace has yet to mature, they are still unable to interface with Space Marine power armour, so are instead allowed to wear a suit consisting of carbon-titanium composite plates. This is still capable of stopping the majority of small-arms fire. In times of relative peace, full Battle Brothers of certain Chapters may take to wearing Scout Armour during periods outside of battle. In games of Warhammer 40,000, scout armour confers a saving throw of 4+, making scouts a fairly resilient unit. Scout armour is a carapace built heavy armour that is also worn by Kaskrin stormtroopers and vostroyans.

Power Armor


Possibly the most prominent feature of the Space Marines is their armor which is a synthesis of many technologies that pre-date even the Age of Strife. The suit is comprised of multiple custom crafted ceramite plates with armored fiber bundles and servos that replicate the wearer's movements and enhances a Space Marine's already superhuman strength, as well as allowing them to easily withstand brutal attacks that would rip a normal human apart. The armor itself can also act as a self-containing environment for the suit's owner, protecting the space marine from anything including the darkness of deep space and the most toxic environments the universe can provide. The armor interacts with the space marine through the sacred Black Carapace, a subcutaneous membrane that allows the marine's internal organs to interface directly with the suit of power armor, making the armor in essence an extension of the wearer's body. The most current armor pattern is the MkVII or Aquila pattern and remains the most mainstream suit of armor in use, it is however not uncommon for parts of older armor to be used to replace damaged areas as this saves precious resources. An example is some marines that have rivets on certain parts of their power armor. These pieces are from the crusade pattern armor and protect just as well as their updated counter parts since the only real change in armor through the patterns is auxiliary systems. What few know is that each space marine's armor is so specific to its wearer that it can not be worn by 2 different marines, so precious is his armor that each space marine swears solemn oaths to honor and maintain its spirit.

Terminator Armor
Tactical Dreadnought ("Terminator") Armor is one of the strongest forms of personal armor and it is the heaviest and most resilient the Imperium has to offer. It was developed for a mid range between dreadnought and standard power armor. It is composed of a ceramite plasteel alloy as an exoskeleton with servo assisted interfaces with the users own neurological and muscular systems to enhance movement. It is able to withstand tremendous punishment, and serves as a solid heavy-weapons platform in open-field combat. Due to it's size, it is best deployed in close quarters such as corridors, where the standard issue storm bolter can be most effective. The First Company of each Space Marine Chapter uses Terminator armor, and only those Marines who earn the "Crux Terminatus" are permitted to wear this precious and rare armor. In games of Warhammer 40,000, terminator armor confers a 2+ armor save and a 5+ invulnerable save.

Artificer Armor
Artificer Armor is the name given to individualized and heavily modified suits of power armor given only to Space Marines who have proven themselves worthy. Artificer armor is a masterpiece of craftsmanship, offering its wearer nearly as much protection as Terminator armor. In game terms, it gives it's wearer 2+ save, but the model in artificer armor cannot use as potent weapons as the model in Terminator armor.

===Perseus Armor=== Perseus armor is given to high ranking space marine terminators, making them heavy assault terminators. They always use heavy bolters, no matter the cost. In-game, Perseus armor gives the wearer 3+ save, but the model can not move and fight in the same turn, no matter how you play.

Vehicles
The Adeptus Astartes have access to some of the most powerful and rarest vehicles in the Imperium. They are all treated as holy relics, and lovingly maintained by the Chapter's Techpriests. Many vehicles are ancient STC designs, barely understood by the current Adeptus Mechanicus.

Dreadnought
The greatest of Marines who fall in battle with grievous and often life threatening wounds are placed into a dreadnought that allows the pilot to live through a sophisticated array of life support machines. The pilot of the dreadnought is hooked straight into the dreadnought to preserve him and allows the Marine to control the dreadnought as if it were his own body. It is a great honor to be deemed worthy enough to enter a dreadnought and keep fighting in the Emperor's name for many more millennia, for the knowledge to create new dreadnoughts has been lost over the long centuries. Some marines that have been placed in the great dreadnoughts have been around dating back to when the Emperor himself still walked among his people. When the dreadnoughts are not needed by the chapter, they are placed back into the chapter's chapel to sleep away the centuries until they are needed once more.

Rhino
A fast troop transport, a Rhino APC (Armored Personnel Carrier) can hold up to ten Space Marines not including the two crew members. The chassis of the Rhino is very versatile, and serves as the basis for some of the other Space Marine vehicles. The Rhino can have pintle-mounted weapons.

Razorback
A Razorback is a variant of the Rhino chassis that sacrifices some troop capacity for additional firepower. Razorbacks are commonly mounted with twin-linked heavy bolters or twin-linked lascannons on a single turret on the chassis, and are excellent for firepower to smaller squads. They can, however, also utilize Assault Cannons, or Multi-Meltas. With the addition of the turret, troop capacity is limited to six Marines.

Predator
The Predator is a heavily-armored Rhino variant that is used as a light tank. With the added weapons it offers no space for troop transport. Armed with either an autocannon or twin-linked lascannons on it's main turret, it can also have heavy bolters or lascannons mounted on sponsons to either side as well. The Blood Angels Company is one exception in that they have been known to field a 'Baal' variant of the Predator. The Baal Predator is equipped with a twin-linked Assault Cannon on it's main turret and single Heavy Flamers or Heavy Bolter mounted to either side on sponsons as well.

Whirlwind
Being a mobile force, the Space Marines have little need for artillery. However, when it is called for, they can utilize the Whirlwind, which is another Rhino variant armed with a long-range missile pod, and can bombard enemy positions in preparation for attack. Whirlwinds offer two types of ammunition in the forms of Frag and Krak missiles, depending on the threat they will engage. As with the Predator there is no room left inside these tanks for troop transportation, after they are outfitted.

Vindicator
When attacking fortified positions, Space Marines use a Vindicator, which fills nearly the entire Rhino chassis with the massive, snub-nosed "Demolisher Cannon", capable of blasting through the thickest walls. This weapon has proven so effective that the Iron Warriors Traitor Legion makes it a point to scavenge these for their own use whenever possible.

Land Speeder
Incredibly fast, the double-seat Land Speeder ground-effect vehicle is used to attack enemy fortifications and heavy weapons from the air. Although it is well-armed it has little armor and relies on speed and rapid strikes for protection.

Its other variants include;


 * The Tornado: The Tornado pattern Land Speeder mounts twice as many heavy weapons as the basic Land Speeder and can also choose from a wider variety of weapons, able to mount an assault cannon or a heavy flamer.


 * The Typhoon:The Land Speeder Typhoon, is extraordinary at anti-personnel actions on the battlefield. The Typhoon mounts a twin-linked Typhoon Missile Launcher. The Typhoon missile inflicts a hard hit with the Blast template at long range and rarely misses since it is twin-linked. The Typhoon variant's only real drawback is its lack of versatility - the Typhoon missile launcher is excellent at destroying infantry or light vehicles, but almost useless against even medium armour such as the Eldar Falcon or Tau Devilfish.


 * The Tempest: Sporting better armour, an assault cannon, and a twin-linked missile launcher, the Tempest is among the most feared versions of the Land Speeder. The Tempest has a bit of a difficult combination of weapons - the assault cannon has a medium range while the missile launcher fires out to a decently long range in comparison. Better frontal armour means that the Tempest can usually get in close to troops without much worry. Also, Tempests are not upgrade variants like the Tornado and Typhoon. Instead, the Tempest is a separate Fast Attack vehicle option, and normally are only be fielded in squadrons of one model. This means a maximum of only three Tempests are fielded in a standard Space Marine army. However, the twin-linked firepower of the Tempest's missile launcher and its increased armour make the Tempest a force to be reckoned with, used regularly for an open Fast Attack choice. The Tempest is no longer available as an option in the most recent Space Marine Codex.


 * The Storm: The latest of the Landspeeder variants to be introduced to the game, the Storm is a transport vehicle for the exclusive use of the Space Marine Scouts. It sports a larger cargo compartment for the accommodation of five of the aforementioned Scouts, as well as a Jamming Beacon and a Cerberus Launcher. As a trade-off, it can only take one weapon, rather than the usual two, and has fewer choices as to which weapon it will take.

Land Raider
The Land Raider is one of the most powerful tanks at the Imperium's disposal, and also one of the rarest. A chapter is lucky to have more than five at its disposal. It can transport troops into battle, carries enough weapons to blast its way though nearly any defense, and has armor thick enough to withstand massive amounts of fire.

The normal Land Raider pattern is called the Phobos. It carries a hull-mounted, twin-linked heavy bolter able to turn light infantry into sludge. It also carries two twin-linked "Godhammer" pattern Lascannons in its two side sponsons, making the Land Raider an extremely formidable foe for armored vehicles, able to stand up for itself in any fight against any other vehicle, and come out victorious almost all of the time.

Land Raiders are also equipped with a "Machine Spirit", an Artificial Intelligence crafted by the Adeptus Mechanicus. The Machine Spirit is smart enough to move the tank and fight even without a crew. It enables the tank to move even when the crew has been stunned, and is able to operate one weapon of the player's choice, to shoot at a target. However, the artificial intelligence of the machine spirit is nothing compared to the battle-hardened Space Marine crew of the Land Raider, and as a result, accuracy suffers considerably.

Land Raiders were once used by all branches of the Imperium's armed forces. During the Horus Heresy, the Emperor ordered that their use be restricted to the Space Marines, as they were at the forefront of the wars. The popularity of this mighty war engine was so great, that a whole Forge World, Anvilus 9, was entirely turned over to Land Raider production. But, at the beginning of the Horus Heresy, Anvilus 9 was overrun by renegade techpriests. Other Forge Worlds of the Imperium also ceased to function, either suffering the same fate as Anvilus 9, or became neutral, leaving only a small number of loyalist Forge Worlds behind, and Land Raider production suddenly slowed to a trickle.

With Horus' forces threatening to overrun Terra, the planet where the Emperor is stationed, the Emperor decreed that all Land Raiders still at the loyalist side were to be reformed for exclusive use by the Space Marines, who were at the forefront of the fighting. Once the Horus Heresy has been crushed with the sacrifice of the Emperor, the decree of exclusive use remained in place, even after the ascension of the Emperor to the Golden Throne, as none dared to revoke His most holy commandments. Thus, the decree remained in place for the last ten thousand years.

Land Raider Crusader
The Land Raider Crusader is nearly identical to the standard Land Raider, but is armed to provide short-ranged, anti-infantry support. The Crusader was originally developed by the Black Templars Chapter, but was eventually authorized for use by other Chapters (who, it should be noted, had already been using them for some time beforehand.) All Chapters are now only allowed to have 1 in their army, except the Black Templars

The Land Raider Crusader is armed with a hull-mounted twin-linked Assault Cannon turret, and sponson-mounted Hurricane Bolters (essentially six bolters linked together). It is also equipped with a Multi-Melta to burn through armored walls, and its front is studded with fragmentation launchers to assist the troops disembarking from its front ramp. The removal of the Lascannon sponsons allows for greater troop capacity. The Crusader may transport 8 Marines in Terminator armor, or 15 Marines in standard power armor.

Land Raider Redeemer
The Land Raider Redeemer is an evolution of the Crusader, created by the Salamanders Chapter. The Redeemer retains the assault cannon and frag launchers of the Crusader, but replaces the hurricane bolter sponsons with flame projectors. These flamestorm cannons are able to purge even a well-defended bunker complex in seconds.

Land Raider Terminus Ultra
Released in the Apocalypse series, the Land Raider Terminus Ultra Pattern is one of the Imperium's best tanks. It is a Land Raider with 2 side-mounted Twin-Linked Lascannons, 2 side-mounted Single-Linked Lascannons, and a Twin-Linked Lascannon on the roof. The only downside to this vehicle is that it can't carry troops, yet the sheer fire power fully makes up for it.

First Founding
The Space Marines were originally divided into 20 vast Legions, each Legion being based on genetic material from one of the original Primarchs. When 18 of the Primarchs were rediscovered during the Great Crusade, they became leader of the Legion based on them. During the Horus Heresy half of the Legions turned traitor.

Loyalists
These Legions remained loyal to the Emperor during the Horus Heresy. They were subsequently split up into smaller Chapters, one of which retained the name of the original Legion.

Traitors
These Legions sided with Horus and the forces of Chaos in the Horus Heresy. After their defeat they fled into the Eye of Terror becoming the Chaos Space Marines. Note - the Traitor Legions' homeworlds were later destroyed. with the exception of the Alpha Legion's homeworld which was never discovered.

Unknown
There are two other First Founding Legions whose names and histories are totally unknown. Following the Horus Heresy all historical records mentioning these Legions were revised or destroyed, in order to erase them from Imperial history. Given the totalitarian nature of the Imperium, it seems likely these Legions were completely removed from all historical records for bringing some sort of shame on the Imperium.

Later Foundings
After the Horus Heresy, it was determined that the Legions were too powerful to be controlled by one man. In what is known as the Second Founding, the existing Legions were broken up into the Chapters which remain the primary organization of the Adeptus Astartes to this day.

In subsequent Foundings, the Imperium has created new Chapters of Space Marines, using gene-seed sampled from existing ones. Many of these successor Chapters still keep the memory of their progenitor Legion or Chapter, and maintain their methods of operation and battle.

Examples of Successor Chapters include:

For a list of the Space Marine Chapters see Space Marine Chapters
 * Astral Claws: a Chapter led into Chaos by their traitorous Chapter Master, igniting the Badab War. They currently form a group of rebel Marines known as the Red Corsairs, who ruthlessly attack supply lines in the name of Chaos.
 * Black Templars
 * Crimson Fists
 * Doom Eagles
 * Executioners
 * Fire Hawks
 * Flesh Tearers
 * Howling Griffons
 * Lamenters: an unfortunate Chapter who fought on the losing side in the Badab War, before being devastated by the Tyranids.
 * Mantis Legion
 * Marines Errant
 * Marines Malevolent
 * Raptors: Successors of the Raven Guard who specialize in jungle warfare.
 * Relictors: a radical Chapter that utilises the weapons of Chaos to destroy the minions of Chaos themselves. This brings them into conflict with the Inquisition but ironically also finds them favour with radical Inquisitors.
 * Scythes of the Emperor: a Chapter of Space Marines who were all but destroyed by the Tyranids. Their armour was black and yellow, with a yellow scythe symbol on the shoulder panels.
 * Sons of Guilliman: A Chapter that originally was a part of the Ultramarines.
 * Soul Drinkers : A Chapter loyal to the Emperor, but not to the corrupt Imperium, has mutating Gene-Seed.
 * Subjugators
 * White Consuls
 * Iron Snakes: A newer Chapter of Space Marines created by novelist Dan Abnett

Purity Seal
The Purity Seal is often awarded to Marines who show themselves to be "morally pure" by their words and deeds. Also, before a campaign, the Chapter's Chaplains will mark certain individuals with litanies. Each seal has a different blessing or invocation from one of the Chapter's Chaplains and is often replaced with a more permanent electrum casting of the seal.



Marksman's Honor
This device is the Marksman's Honor. Acts of remarkably accurate shooting or consistent performance with targeting are marked with this award. The Codex insists that those warriors who prove their accuracy in combat should be singled out so that their skill may be instantly commanded when necessary. The badges themselves are believed to have been constructed by taking gold bolter shells cases, fired in battle from the boltgun of Roboute Guilliman himself, and encasing them in the award.



Imperial Laurel
The Imperial Laurel denotes veteran status and is awarded to Marines who perform "acts of valor leading to great victory" or "an act of extreme bravery". It is often sculpted onto the helmet or worn as a crown, the Wreathed Skull is another common design variation. The Codex Astartes states that all Company Standards be carried into battle by warriors who have proven themselves, so all bearers must first wear the Laurels.



Terminator Honors
The Crux Terminatus, or Terminator Honor Badge is given to Marines who have been trained in the use of Terminator Armor. Sergeants and officers wear variations of the badge to signify their rank. It is said that each of these badges has a fragment of the Emperor's own armor within it.



Skull and Motto
In Imperial iconery, the skull is incorporated into many devices. The Skull and Motto is one example. It is used when the other specified honor badges would be inappropriate, and often the motto is simply one word. The badge can be found on shoulder pads, banners, leg armor, and even vehicles



Imperialis
The Imperialis was originally the campaign badge used by loyal Marine Chapters during the Horus Heresy. Over time it has evolved into the "honor of righteous victory". It's most commonly seen carved into Marine chest armor, but can also be found on banners or atop their poles.



Iron Skull
The Iron Skull is the Codex insignia for Sergeants, and is displayed on the helmet and/or shoulder pad of the Marine as a sign of rank. Generally accepted convention is that a red skull device is used to represent it.



Iron Halo
The Iron Halo is awarded to Marines that show "exceptional initiative". It is the Codex insignia for Squad leaders, and is displayed on the helmet and/or shoulder pad of the Marine as a sign of rank.



Prime Helix
The Prime Helix is the symbol of the Apothacarion, worn by Medics. The design represents the Gene-seed DNA, and the color represents the sacrifice that every Marine is willing to make.