Combat skin

Combat Skin is a Forerunner term relating to body armor. The Forerunners had a classification system for combat skins, running from Class 1 to 12, and possibly above.

According to 343 Guilty Spark, the Human MJOLNIR Mk.V Battle Armor is ranked on this scale as Class 2.

Armor of the Forerunner
Not much is known about Combat Skin. The term first comes up in the level Library when 343 Guilty Spark wonders why John-117 had brought "such ineffective weapons" to combat the Flood, and recommends that the Chief upgrades from the MJOLNIR armor, which, according to some Forerunner ranking system, the criteria of which is not gone into, is only Class 2, which Guilty Spark says is ill suited to combat the Flood. He suggests that Master Chief upgrade to at least a Class 12 Combat Skin.

This implies that the Forerunners made extensive use of armor, presumably powered armor, to the extent where there were at possibly at least twelve or more ranks of effectiveness or usability.

What Does the Class System Mean?
Because so little is mentioned about combat skins, there is much speculation about exactly what the combat skin rating indicates. The obvious interpretation is that the combat skin ranking system measures raw power, and that a class 12 combat skin is 10 ranks higher in protection and power than a class 2.

Armor Class
Another interpretation is that the class system does not measure raw power, but rather classifies armor by its role. Later in the game, 343 talks about the Flood changing the atmosphere and says "Your Environment Suit should serve you well..." It could be a class 2 combat skin functions well as an environment suit, whereas a class 12 combat skin is specifically designed for combating the Flood.

Environment/Combat Suit
Another theory states that a combat skin may also be an environment suit, an example; a HAZMAT suit is an environment suit, but has no further use in combat, while a suit of Kevlar provides physical protection but no environmental protection. John-117's "combat skin" also functions as an "environment suit;" this can overlap with other theories, as a useful environment suit may lack in either pure power or suitability for its role in combat.

Shielding Theory
A last theory states that "combat skin" does not refer to armor at all, but rather shielding; the disparity in power between the Master Chief's shields in comparison to that of the Forerunners is obvious. This is again compatible with either the power or role theory, as class 12 shielding may be powerful enough to shrug off any Flood attack, or specifically designed to handle the damage the Flood put out.

Trivia

 * The difference in nomenclature has led some to believe that the two items 343 refers to are different, i.e. armor is an "environment suit" and the body is the "combat skin."
 * Also in Halo: The Flood the Prophet that is stationed on Halo tells 'Zamamee that his armor is from Forerunner technology.
 * In Halo: The Flood, John-117's interpretation of the Combat Skins is "If there's a battle suit six times more powerful than the MJOLNIR armor, I'll be first in line to try it on."

Related Links

 * MJOLNIR armor
 * Semi-Powered Infiltration Armor
 * Elite Personal Energy Shield
 * Body Suit