Support weapon

Infantry support weapons are a class of crew served, man-portable, specialized weapon systems. By design, they require an "assistant" crew of more than one individual to function at optimum efficiency due to its operational complexity, such as requiring one person to load while another fires, or another person to carry a bipod and additional ammunition. The weight and bulk of the weapon system often also necessitates multiple personnel for transportation.

Description

When used by individuals, these weapons are much larger than the standard shoulder-fired military service weapons, and require two hands to heft. Consequentially, players move more slowly while holding them, and cannot duel-wield, throw grenades or melee opponents while holding the weapons, thus they become very vulnerable to enemy grenades, snipers and vehicles, since they almost can't be dodged.

While originally designed to be fired from stationary mounts, individuals are known to have ripped them off of their bases and carried with the ease of standard infantry weapons. Thus while they have limitless ammunition while in their mounts, once removed and carried the ammo they have becomes limited. Also, the accuracy of the turret can become more of a problem, being handheld of course.

List of infantry support weapons

AIE-486H Heavy Machine Gun - the machine gun turret featured in Halo 3 and Halo 3: ODST.
LAU-65D/SGM-151 missile pod - missile launcher featured in Halo 3 and Halo 3: ODST.
M247 General Purpose Machine Gun - the machine gun turret featured in Halo 2 and Halo 2: Anniversary.
M247H Heavy Machine Gun - the machine gun turret featured in Halo: Reach, Halo 4, and Halo 2: Anniversary.
M343A2 chaingun - the machine gun featured in Halo 5: Guardians.
M555 Gauss cannon - Gauss cannon featured in Halo 5: Guardians.
M7057 flamethrower - flamethrower featured in Halo PC, Halo 3, and Halo 3: ODST.
M80 missile launcher - missile launcher featured in Halo 5: Guardians.
Type-42 plasma cannon - plasma cannon featured in Halo 2 and Halo 2: Anniversary.
Type-52 plasma cannon - plasma cannon featured in Halo 3, Halo 3: ODST, Halo: Reach, and Halo 4.
Type-58 plasma cannon - plasma cannon featured in Halo 5: Guardians.
Z-520 splinter turret - a Forerunner turret, featured in Halo 5: Guardians.

Trivia

In Halo PC, Flood combat forms have the animation and programming required to wield the Flamethrower. However, when they shoot it at a player directly in front of them or below them, they point it at a 45 degree angle in the air, making them not so effective when wielding it.^[1]
In Halo 3, If Thel 'Vadam is killed near a support weapon that is off its mount, he will use it when he gets back up.^[2]
Other than the Flamethrower, all deployed support weapons in Halo 3 have limited ammo regardless of whether the infinite ammo option is turned on or off.
Standard weapons like the Brute Shot and the Sentinel beam function similarly to support weapons: they are held the same way, and have more firepower than normal weapons though the player can still melee or throw grenades and the player can only carry one other weapon while wielding them.
Support weapons are especially useful in multiplayer because the third-person point of view allows the wielder to see around corners without making them visible or vulnerable to enemy fire.

Gallery

A Spartan-II using a flamethrower in Halo: Combat Evolved.
A Marine using an M247 during the Battle of Mombasa in Halo 2.
A Spartan-II wielding a Missile Pod in Halo 3.
A Spartan-II using an AIE-486H in Halo Wars.
An ODST using an AIE-486H in Halo 3: ODST.
A Spartan-III using an M247H in Halo: Reach.
A Spartan-IV using an M247H in Halo 4.
A Sangheili using an M247H in Halo 2: Anniversary.
A Spartan using a machine gun during the Battle of Mombasa in Halo: Spartan Strike.
Edward Buck firing a chaingun turret during the Battle of Meridian in Halo 5: Guardians.