The Adeptus Astartes tactical, operational and strategic capabilities on a unit by unit level are much greater than those possessed by other military organizations. This increased capability is based off the fact that individual marines are simply biologically superior, better equipped and more highly trained than any comparable military force.

The individual space marine is much stronger, tougher, intelligent and resilient. Going by the fluff we can figure that the average space marine is roughly 8 feet tall and 450 pounds. This will give them a benchpress of approximately 400 pounds, ON AVERAGE. They are also faster than average humans, generally twice as fast on average, giving them the capability to conduct a march at roughly 10 miles an hour with a combat load, which for a space marine (without armor) would be ~300 pounds of equipment, which is roughly twice the equipment that a normal human can carry. This gives them at least twice the combat endurance as other human units, which is generally 72 hours, but can be extended to 5 days… The capabilities of an unarmored space marine allow for operations in low light conditions (including night time operations) and thus will take no penalties to speed while operating at night, unlike normal troops.

A comparison of capabilities is shown in table 1 below.

The weaponry for a space marine will be a bolt pistol, a close combat weapon, bolt rifle, heavy bolter, or sniper rifle. In comparison, the bolter is a 20mm weapon with recoil compensation, automatic targeting, smart-link capabilities, laser target designator and fires either incendiary, high explosive, or armor piercing rounds. The main difference between bolt pistols, bolt rifles and heavy bolters are their range, rate of fire and internal ammunition capacity. In comparison with either laser rifles or current technology small arms, the bolter exists at the upper end of any comparable spectrum. A bolt offers terminal ballistics equivalent to that of current 20mm weapon systems, albeit with much shorter ranges except for the heavy bolter. The bolt pistol and bolt rifle offer comparable ranges with small arms of their class (heavy pistol, heavy rifle) that have been heavily modified for accuracy, but they are not in a separate class for either range or accuracy.

Sniper rifles for the Astartes would classify as anti-material rifles in other military organizations, offering accurate placement of heavy kinetic rounds on targets up to several thousand meters distant with low, or no signature. This allows the engagement of lightly armored vehicles at long distances with high PK on most biological targets with low possibility of accurate return fire.

The equipment of the space marine increases their capabilities as well. The base armor protection of an UNARMORED space marine is considerable when factoring in their increased muscle density, toughened skin, thickened bone, regenerative and clotting capabilities, mental resilience to avoid shock and the black carapace. These factors give an unarmored space marine the equivalent of class IIIA soft armor, which makes them all but immune to artillery fragmentation and pistol rounds. The standard armor package for scouts is equivalent to class IV hard armor and provides armor protection against all small arms and AP rounds, which reduces the casualty rates to almost negligible levels against small arms. Only multiple hits are capable of damaging space marines in armor, generally requiring 6 hits with a 5.56mm caliber weapon, 4 hits from a 7.62mm caliber weapon or 2 hits from a .50 caliber weapon to injure a space marine. Even when injured, a space marine heals at roughly 4 times the rate of human soldiers, thus even traumatic injuries can see survival rates of 98% and a return to active duty within days even from burns and deep penetrating wounds such as gunshots.

The standard Astartes powered armor provides even greater armored capabilities, increasing their armor protection up to taking multiple hits from heavy machine guns (14.5mm to 25mm caliber). The terminator armor increases this protection further. The standard Astartes powered armor is equivalent to a lightly armored wheeled tactical vehicle (FRAG IV equivalent), while the terminator suit is the equivalent of an infantry fighting vehicle, able to withstand multiple impacts from 20mm to 25mm armor piercing fin stabilized discarding sabot depleted uranium impacts.

The capabilities of a human vs a space marine in various levels of armor protection is shown in Table 2, below.

Without armor, space marines have low-light vision, which is the equivalent of NVG’s whereas with armor, space marines gain the benefits of full color thermal optics, laser range finder, ballistic computer, full navigational system (both GPS and INU capable), short, medium and long range LOS secure burst radio communications, full suites of tactical command and control software tools, short range radar, noise amplification and nullification capabilities, Full NBC protection, universal translators, video and audio recording, expert systems for many combat tasks such as electronic warfare, cyber capabilities, repair operations, and the ability to eat and void waste with only minimal time expenditure (~1 minute).

The final piece is the training of a space marine which is what truly allows the organization to outperform other military organizations. Each Astartes has a minimum of 7 years of training before engaging in their first battle. Due to this, they have the equivalent of five years of training (accounting for the surgery and recovery time). Since space marines operate on 4 hours of sleep or less normally (instead of 8), they have no “time off”, they have increased memory retention and are chosen for increased intelligence (with the minimum IQ generally being around 140), for every year of time, they have the equivalent of 4 times the ability of a normal human to engage in training. Thus the 5 (effective) years of training that a space marine receives prior to any mission is equivalent to 20 years of training and experience for normal human soldiers.

Each space marine is fully trained in all infantry centric tasks as well as those which are often considered to be special operations by other forces. Space marines can be inserted from space, air, ground or undersea vectors. They are all marksmen of expert caliber as well as unarmed combat experts. They can track, infiltrate and operate for days without saying a word, communicating only by their chapter’s unit specific sign language. They can survive indefinitely as long as there is sufficient food to forage. They can operate unaided in any terrestrial terrain from -100o F to +140o F and from 200m below sea level to ~9,000m above sea level. This means that a space marine can literally swim the English Channel or jog up Mount Everest every day for roughly 3 days in a row before they would be exhausted.

Their skills would include infantry, armor, artillery, piloting, naval ship operation, space ship operation, guerilla warfare, close quarters battle, boarding actions, intelligence collection and analysis, planning, maintenance and field expedient repair of all their organic weapon systems, tactical casualty care, fire support and logistics. Due to this training, and their ability to rapidly gain intelligence, plan, choose a course of action, and execute, the space marines have no need of dedicated staff positions. The ability for every space marine to operate all of their organic vehicles is also a benefit, and the fact that they are responsible for their own maintenance also reduces their need for logistic or maintenance support.

To fully understand the benefit of these gains, it is necessary to understand that space marines are capable of drastically reducing the required manpower for an operation. As an example, we will examine the manpower savings that can be realized. For a 3000 man imperial guard mechanized infantry regiment, the following personnel are not required by Astartes forces:

Administration and Staff: ~1000 There is no need for multiple layers of command authorities. The expert systems and data net capabilities of the armor allow for the rapid transmission of orders to any and all troops that require the information

Military Police/ Discipline: ~100 Space marines are not subject to discipline problems that are not solved by absolution or death. Battle brothers watch out for each other

Signal: ~200 Powered armor negates the need for special communications systems, as they are already built in and mobile

Chemical: ~50 Powered armor eliminates the need for special chemical troops.

Intelligence: ~300 space marines are fully qualified to gather, analyze, fuse and report all manner of intelligence and are trained in interrogation if necessary. The data sharing capabilities of the powered armor allow for rapid dissemination of all tactical data.

Engineers: ~100 Space marines are not defensive troops, but rather offensive troops and are fully trained on all breaching techniques via the use of thunder hammers, assault shields, chain fists and power weapons.

Maintenance: ~200 Space marines are responsible for the maintenance of their own equipment

Medical: ~200 While Astartes do require medical attention, an apothecary, in conjunction with Astartes powered armor and the inherent regenerative capabilities of a space marine is able to provide superior care to a human surgical team. This allows for a total manpower savings of 200 personnel since there is no requirement for transportation of the casualty from the location of injury to the point of treatment. Space marines either receive treatment and survive or they die immediately from trauma. A space marine who does not die within 30 seconds of injury has a 75% chance of recovery with only rudimentary first aid, and a 95% recovery rate when treated by an apothecary.

Transportation: ~200 space marines are mobile and do not require transportation, they will move themselves and their own equipment. This means that there are no dedicated drivers, gunners, vehicle commanders. There are troops and vehicles and the troops man any vehicles when necessary.

Logistics: ~200 space marines are responsible for planning and executing their own logistic resupply plans, the vast majority of which are delivered via orbital drops.
Thus space marines are able to have a manpower savings of roughly 1/3 while increasing the protection and firepower available. Thus for a mechanized infantry regiment of 3000 people has the combat power of 16 artillery pieces, 60 tanks, 60 armored fighting vehicles, 10 wheeled recon armored vehicles and 300 infantry. In comparison, a 1000 man space marine chapter fields 30 heavy tanks that double as troop transports, 50 heavy infantry that are the equivalent of tanks and 850 infantry that are the equivalent of armored fighting vehicles in firepower and tactical mobility.

If firepower can be rated as 6 for artillery, 5 for heavy tanks, 4 for tanks, 3 for armored fighting vehicles, 2 for wheeled recon armored vehicles and 1 for infantry, then the mechanized infantry force has a firepower of 956 with a manpower allotment of 3000 (.318 firepower per man). The Astartes force would have a firepower of 2900 with a manpower allotment of 1000 (2.9 firepower per man) which makes every space marine the equivalent of 9.12 Imperial Guard as a tactical unit. Thus a full chapter of Astartes have the same firepower capability of a full division of IG, which again holds true for the rough estimate of 1 AA = 10 IG.

In addition to the tactical power of the AA, there is also a strategic element. There is a specialized IG regiment for each role the IG is expected to pursue such as siege regiments, armored regiments, mechanized infantry regiments, light infantry regiments, special operations regiments, airborne regiments, air assault regiments, artillery regiments, amphibious/marine regiments, garrison regiments, and space assault regiments that specialize in boarding actions. Unlike those units, a space marine chapter is actually not specialized, but rather deploys with their ship configured to take any of those roles, although garrison troops is not a mission that any AA would stoop to perform. Although the extreme physical capabilities of a space marine make them the equivalent of 10 other troops in a tactical role, the ability of each chapter to fulfill the roles of up to 10 specialized IG regiments for strategic planning.

Thus, instead of having to get 6 regiments of assault troops, one regiment of siege troops, a regiment of artillery troops and two regiments of armored troops…a single space marine chapter can be tasked with that operation as the chapter can fulfill all of those roles in succession without the need to do anything other than transition into or out of vehicles, thus having one chapter of 1000 space marines actually take the strategic place of 10 IG regiments, making 1000 space marines the equivalent of 30,000 IG. This is the true worth of the Astartes.

In conclusion, the combined effects of genetic engineering, advanced technology and superior training make the AA the pinnacle of military technology, turning the average infantryman into the equivalent of an armored fighting vehicle and a squad of dismounted troops. On an individual level, the AA are the equivalent of two to three IG soldiers. With the addition of powered armor, the individual trooper becomes the equivalent of 9 to 10 normal IG soldiers. When the chapter is measured on a regimental level, however, each chapter can replace up to 30,000 normal IG troops, and when measured against the additional support requirements of 3 divisions (which is up to 1,000 additional troops for a Division HQ) and a full corps (another 1,000 troops for a Corps HQ), then each Astartes is worth up to 34 IG troops on a strategic scale, not to mention all of the additional logistical support that the Navy has to provide for the troops such as ammunition, food, casualty evacuation, etc.

Table 1:
Factor Human Space Marine
Speed/duration: 10 mph sprint/30 seconds 20 mph sprint/ 2 minutes
7 mph run/10 minutes 15 mph run/30 minutes
5 mph jog/ 1 hour 10 mph jog for 12 hours
4 mph march w/ load/10 hours 10 mph for 40 hours
2.5 mph walk w/ load/20 hours 5 mph for 60 hours
Combat Endurance 72 hours normal 7 days normal
5 days extended 15 days extended
Patrol Radius 2.5 miles per hour (day) 5 mph day or night
1 mile per hour (night)

Table 2:
Human IIIA IV UA AA Armor PA TA
9mm Injury 2 4 N/A 4 N/A N/A N/A
Disabled 3 6 N/A 6 N/A N/A N/A
Killed 4 10 N/A 10 N/A N/A N/A
5.56mm Injury 1 1 4 1 5 10 AP 200 AP
Disabled 2 2 5 2 7 15 AP 500 AP
Killed 3 3 6 3 9 30 AP 1000 AP
7.62mm Injury 1 1 2 1 3 5 AP 100 AP
Disabled 1 1 3 1 4 10 AP 200 AP
Killed 2 2 4 2 6 15 AP 500 AP
.50 cal Injury 1 1 1 1 1 2 20 AP
Disabled 1 1 1 1 2 3 30 AP
Killed 1 1 2 1 3 5 50 AP
14.5mm Injury 1 1 1 1 1 1 5
Disabled 1 1 1 1 1 2 10
Killed 1 1 1 1 1 3 15
20mm Injury 1 1 1 1 1 1 2
Disabled 1 1 1 1 1 1 3
Killed 1 1 1 1 1 2 5
25mm Injury 1 1 1 1 1 1 1
Disabled 1 1 1 1 1 1 2
Killed 1 1 1 1 1 1 3