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.

Gameplay
When used by individuals, these weapons are much larger than the standard shoulder-fired military service weapons, and require two hands to heft. As a consequence of their weight and bulk, players move more slowly while carrying them, and cannot duel-wield, throw grenades or make melee attacks while wielding the weapons; this increases vulnerability to enemy grenades, snipers, and vehicles, since the reduced mobility decreases ability to make evasive maneuvers.

While originally designed to be fired from stationary mounts, these weapons can be removed from their mountings or tripods and carried as man-portable heavy weapons. Effectiveness is reduced, however, by a number of factors; while mounted, the benefit of feeds from ammunition stores present in the mounts provide effectively unlimited ammo, but once removed and carried, the ammo loaded in the weapon is limited. Furthermore, accuracy and stability is typically diminished when fired while handheld, compared to firing the weapon from its mount.

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, Halo 2: Anniversary and Halo Infinite
 * M343A2 chaingun - the machine gun featured in Halo 5: Guardians.
 * M70 Gauss cannon - Gauss cannon featured in Halo 5: Guardians.
 * M7057 flamethrower - flamethrower featured in Halo: Combat Evolved for 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 and Halo Infinite.
 * Z-520 splinter turret - a Forerunner turret, featured in Halo 5: Guardians.
 * Scrap Cannon - a Banished spike-firing machine gun turret, featured in Halo Infinite.

Trivia

 * In Halo: Combat Evolved (PC port), 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.
 * 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.
 * 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, unless they are left on their stands.
 * In Halo: Reach, the M247H can be used with infinite ammo in Firefight if the bottomless clip setting is turned on.
 * 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.

List of appearances

 * Halo: Combat Evolved
 * Halo 2
 * Halo 3
 * Halo Wars
 * Halo 3: ODST
 * Halo: Reach
 * Halo 4
 * Spartan Ops
 * Halo: Spartan Assault
 * Halo 2: Anniversary
 * Halo: Spartan Strike
 * Halo 5: Guardians
 * Halo Wars 2