UNSC Army

The UNSC Army is a branch of the UNSCDF primarily responsible for land-based military operations. They deploy primarily from pre-established bases located on a planet's surface as opposed to the Navy Vessels that the other branches of the UNSCDF deploy from.

Background
Little is known about the UNSC Army, due to the fact that the Army is a land-based fighting force, and thus does not operate alongside the UNSC Navy as often as the UNSC Marine Corps does. What is known is that the UNSC Army uses different equipment and weaponry from the Marines. Examples include: the M6J Carbine, the MA37 Assault Rifle, and the DMR, in contrast to the MA5B/MA5C Assault Rifles and BR55 Battle Rifle in use by the Marines. All (on-field) soldiers of the UNSC Army wear (different versions, depending on the environment) the UNSC Army Battle Dress Uniform.

Role
It is known that the UNSC Army frequently patrols colony planets, but little is known about the operations they have participated in. Known operations include the Battle of Reach, where Army units assisted SPARTAN Noble Team in defending the planet, the Battle of Earth, where an Army unit tried to aid Marine forces in New Mombasa and was annihilated in the attempt, and the Battle of Mare Erythraeum on Mars, where Colonel James Ackerson led an unknown number of Army forces against the Brute commander Lepidus and his army. Unlike the Marines, who take offensive action against the enemy from naval vessels, the UNSC Army launches offensive operations from land bases against land based targets and are used in capturing and establishing UNSC-held territory.

It is also unknown what role the Army played in Operation: TREBUCHET and what actions they were apart of, although TREBUCHET might have been a Marine exclusive counter-terrorism operation.

There are also a number of Army special forces groups. The only known such group is 3 Charlie, a reconnaissance team which, along with Noble Team, is a part of Special Warfare Group Three.

Trivia

 * The helmets worn by Army soldiers appear to be similar to those worn by the Marines; and may be the base of the MJOLNIR Military Police armor permutation in Halo: Reach's Armory. Additionally, their shoulder pauldrons are almost identical to the GUNGNIR shoulder pieces and the UA/NxRA utility on the right leg.
 * It's interesting to note that female army soldiers have hair descending down from their helmets, possibly showing that the Army is more lenient with its rules on hair length compared to the Marines (where all female Marines seem to have crew cuts).
 * The UNSC Army makes its in-game debut in Halo: Reach, in which UNSC Army soldiers, Marines, and ODSTs have their own service tags showing their name and rank. Some of them are named after Bungie and Roosterteeth employees.
 * The Halo: Combat Evolved Manual, states that UNSC Marines &quot;They're the best of the best, but they're only human.&quot; This is odd due to the fact that Army Troopers in Halo: Reach are far more skilled in combat than UNSC Marines, for example, 8 Army Troopers Privates armed with 5 Assault Rifles, 1 DMR, 1 Shotgun and 1 Sniper Rifle can - On Normal Difficulty - hold off 5 waves of Covenant infantry, each wave consisting of 3 Grunt Majors, 2 Jackal Majors and 3 Elite Ultras, with a total of 25 Grunts, 10 Jackals, 15 Elites. The same number of Marines armed with the same armament would never survive in the same situation. This could be due to the fact that the A.I. in Halo: Reach was upgraded for your allies as well as your enemies.
 * Oddly, if you listen closely to the transmissions and dialogue in Reach, the UNSC Army is never mentioned by name. The soldiers are called troopers, but there is never a definitive mention of the branch.
 * The UNSC Army in campaign is often confused for the UNSC Marines due to the fact Marines almost always accompanied the player in previous Halo games. However, the UNSC Army is entirely different from the Marines.
 * Strangely, sometimes with the IWHBYD Skull an Army Trooper will say, if the player stares at him long enough, that he wonders if he were a Spartan and how "cool" it would be able to beat any Marine. This could be scripting error of the Army Trooper accidentally referring to himself and comrades as Marines or this could imply a rivalry between the UNSC Army and Marines somewhat like the ODST rivalry with Spartan II's or the old rivalry between the US Army and US Marines of the 21st Century United States
 * The concept helmet of the Army Falcon Pilot resembles the ODST Helmet. But with transparent visor.
 * It is unknown if it follows any traditions from the former armies of nations from previous centuries, but it is guessed that that the UNSC Army does.
 * Although the UNSC Army is said to be Marines in the Level: Sword Base all the soldiers uphold ranks found in the Army such as Specialist.
 * The UNSC Army seems to be more amazed, and thankful of SPARTAN deployments, possibly due to the fact that they spend less time aboard Navy vessels than the Marines. This is exampled in the level "Exodus", where an Army female asks, "A SPARTAN? Where the hell did he come from?" followed by a male trooper responding thankfully with, "Who cares! SPARTAN! Assist!"
 * It is possible to have four/ five 1st Lieutenants in your party.
 * Some Army Troopers have been seen wearing facepaint in combat.
 * Although the US Army of today tends to use newer equipment than the US Marines, the UNSC Army seems to use older (and lower quality equipment) than the UNSC Marines. It is possible this is due to budget cuts and the need for the better equipment to be used by the frontline Marines than the garrisoning Army units. Another possibility is that the Army is larger than the Marines, who receive better equipment to make up for that.