- “Those things are scary as hell. Ya hear that weird 'whump' sound and even if ya see it comin', you're transfixed, these big green blobs flying at you throwin' off sparks!”— Anonymous Serviceman
The Fuel Rod Gun is a man-portable version of the cannon that is mounted on Covenant vehicles; it is a support weapon that is commonly employed in both anti-personnel and anti-vehicle roles. It appears to be recoil-operated and fires 3.8 cm explosive ballistic incendiary gel projectiles that travel to the target in a parabolic arc.
The design of the fuel rod gun is unique, resembling a large ornament more than a deadly weapon. The body of the weapon is typically black and covered by thick gold plates. Ammunition is loaded into a slot on top of the weapon nearest the user's shoulder, and can hold 5 ballistic projectiles. Because of the weapon's visibility, it is equally effective as a psychological weapon; due to the threat it represents, however, this means that soldiers will often ignore closer, more obvious targets in order to eliminate a Type-33 and its operator.
The Fuel Rod Gun is unique in the way it operates. Its ammunition is placed one on top of the other to form a magazine and then is loaded into the weapon; it is unknown what exactly holds the rods together. When the large "trigger" is pulled, the weapon ejects the projectile at high speeds. It can be assumed that the instant the projectile leaves the barrel of the weapon, the large flash associated with firing the fuel rod gun destroys the caps that are on each end of the fuel rod projectile. The rods are equipped with an activation delay that protects the wielder from explosions caused by carelessly firing fuel rods into nearby objects or in close quarters, however a fuel rod will detonate if they are fired into enemies at point-blank range. The fuel rod gun is used by most Covenant infantry; Type-33s are seen most often being wielded by Unggoy, and, more rarely, by higher ranking Sangheili and Jiralhanae as well. The Type-33 is extremely powerful, and as such the Covenant went to great lengths to ensure it does not fall into enemy hands - it was originally equipped with a fail-safe that would activate under certain conditions, either when the user drops the weapon without first engaging a safety or if the weapon runs out of ammunition and is not reloaded within a certain amount of time. In late 2552, the fail-safe was removed, preventing the weapon from self-destructing, although it may be that some cannons were equipped with it and others were not.
The Covenant fuel rod gun fires an unknown type of incendiary gel. Next to nothing is known about this type of ammunition except that when it strikes a target, it does so with devastating results. When the fuel rod impacts an area or target, it is instantly subjected to temperatures similar to those caused by standard plasma weapon fire. The fuel rod gun shoots the same type of incendiary gel as the Mgalekgolo's assault cannons. Unlike the assault cannon, however, it shoots canisters of the gel approximately 3.8 cm long instead of shooting globs of the material or concentrating its fire into a sustained beam.
The Fuel Rod Gun is an extremely devastating weapon in the hands of a skilled player. Its destructive power is so effective that human forces often focus all of their attention on infantry wielding the weapon. One strike from a fuel rod will instantly kill any light organic target, while infantry and light vehicles immediately outside the kill radius are swatted away by the concussive force of the blast. The Fuel Rod Gun is highly effective against lightly armored vehicles as well, able to destroy them with only a few hits. The weapon takes less time to reload than the rocket launcher, holds more ammo in its magazine, has a slight tracking ability, and a higher rate of fire.
Rods from the fuel rod gun have a smaller explosive radius than the SPNKr. In addition, the fuel rods will arc once in flight and lose their accuracy over long distances, meaning players must compensate in order to strike their intended target. The large size of the weapon obscures the wielder's peripheral vision, and it reduces the speed of weaker infantry holding it unless it is a Spartan or a similarly muscular being carrying the weapon, due to their superior strength. Sangheili are strong enough that in Halo 3, they are capable of wielding the weapon with one hand. The bright color of the weapon makes the wielder easy to spot, even when the weapon is backpacked; the green flash that occurs when the weapon is fired, can also give away the user's position. The fuel rods are also extremely slow in flight. As a result, Fuel Rods are particularly weak against most reconnaissance vehicles (Ghosts, Warthogs, Banshees, Brute Choppers, Mongooses) at long range. This is because the intended target will easily dodge the fuel rod. It also lacks the lock-on and destructive capabilities of the Halo 2 rocket launcher or Halo 3 missile pod. Also, in Halo 3 and Halo: Reach, the fuel rods usually bounce off the ground, missing their intended targets, unless it is a direct hit, or you are directly facing the surface, such as walls and even the Scarab's exterior, although very rarely it does ricochet off of vehicles, and obviously, infantry.
- Assault cannon: Mgalekgolo also brandish a variant of the fuel rod gun known as the assault cannon. It operates differently than the standard fuel rod weapon, specifically in that it is a select fire mode weapon capable of firing either fuel rod mortars or using the rod to generate a superheated beam. The cannon is integrated into the Mgalekgolo's armor and cannot be removed. As such, it is unusable in any of the Halo games.
- Class-2 Projectile Cannon: The fuel rod cannon is a vehicle-mounted variant of the regular infantry-issue fuel rod gun, and as such it is larger and more powerful. Examples of the fuel rod cannon include the Anti-Air wraith's primary weapon and the Banshee's secondary weapon.
The fuel rod gun is best used against armor at medium range and against enemy positions and gun emplacements at long range.
- The fuel rod gun in Halo 2 generally is rarely seen, thus you will not be able to use it often, an exception being on the Arbiter level where a multitude of Heretic Unggoy use it against you when you are flying in a banshee.
- In Halo 3, the fuel rod gun appears far more frequently. The best thing to do with it is to give it to a marine, who then rides in the passenger seat of your vehicle. Marines can also lock on targets with fuel rod gun, even though the player cannot.
- In Halo 2, if you keep a fuel rod gun from the level The Arbiter and carry it over to The Oracle, it is devastating to the Flood. One shot to Combat Forms on Normal or Easy will kill it. Same goes with Infection Forms, but don't waste it on every one of those. If going for Infection Forms, use them if they're in groups of more than 4.
- In Halo PC, the fuel rod gun is best used as a mortar to bombard the enemy base. It has an advantage of being able to hit enemies that are in cover and over hills, a feature otherwise only possible through the use of grenades. If the wielder uses it against vehicles, correct lead is essential. In Halo 2, the fuel rod gun does not appear in multiplayer, nor does it in Halo 3 - however, it can be added through forge.
- Being an effective suppression weapon, one tactic in multiplayer capture the flag is to bombard the enemy base from afar with a fuel rod gun. Furthermore, the gunner can fire from a position obscured from enemy view, owing to the indirect-fire properties of the fuel rod gun. Since the view of the targeted area is mutually obscured from the gunner's position (due to having to compensate for the arc and having to aim high), such is unlikely to kill a player, but it is intended to at least deal cover fire for an assault on the flag, and most likely to inflict damage on the flag carrier. If multiple players carrying fuel rod guns bombarding a base with the aforementioned technique, it is quite devastating. Note that the fuel rod gun's splash damage is similar to that of the rocket launcher. If fired at very close range, the projectile will harm the player slightly.
Changes from Halo: Combat Evolved to Halo PC
- The Fuel Rod Gun can be used in multiplayer.
Changes from Halo: Combat Evolved to Halo 2
- In campaign, the Fuel Rod Gun can be wielded and will no longer "self-destruct" following the wielder's death.
- The Fuel Rod Gun has been redesigned and now has a golden exterior, instead of a purple.
- The Fuel Rod Gun fires five rounds from a magazine rather than a battery.
- It no longer arcs.
- The Fuel Rod Gun has a tracking ability.
Changes from Halo 2 to Halo 3
- The blasts have been weakened to compensate for the cannon's large number of rounds per magazine.
- Projectiles now ignite only after being fired from the Fuel Rod Cannon. Failure to give the rounds time to activate will result in a ricochet if a non-enemy surface is struck at an angle.
Changes from Halo 3 to Halo: Reach
- There is a small thermal-imaging screen on the bottom left side.
Changes from Halo: Reach to Halo 4
- The IR screen has become a lot wider and detailed.
- It is named Fuel Rod Cannon again.
- The projectiles move at a substantially greater speed.
- The aiming reticle is a circular shape.
- It now has a more metallic firing sound.
- When viewed in third-person, the fuel rod cells advance down by one as the gun fires.
- “Those things are scary as hell. Ya hear that weird “whump” sound and even if ya see it comin' you're transfixed—these big green blobs flying at you throwin’ off sparks!”
- “It’s so weird. I don’t know who first called it a fuel rod gun, but it’s kinda funny. I suppose the projectile is reminiscent of how you might expect to see a nuclear fuel rod depicted in a GA cartoon—all glowing green and throwing off sparks.”
- “They’re pretty tricky to handle—first off you gotta get over the fact that there is this glowing, green explosive whatever right next to your head; and it’s not like you can requisition any more ammo for the damn thing—but you can lay down a whole lotta hurt in a very short amount of time I’ll tell you that.”
- “The Type-33s have more in common with the ballistic weapon on the banshee than it does with the weapon that the Mgalekgolo carry around—well, not carry around, but you know what I mean.”
- “I catch a glimpse of green out of the corner of my eye and then there’s this huge “whoomf” and the ‘Hog goes end over end burning with Gaz still at the wheel. I was riding shotty with the M41 so I just unlatched and pushed off when we started going up into the air and there went the ‘Hog and Gaz and all our gear cart-wheeling into the ravine.”
- “No sooner had I put the Unggoy down than Fisk has got a hold of that bad boy and dumps the whole clip into the column—stickies and everything just cooking off—secondaries like mad! Fisk was a crazy bastard he was—wish he was still with us.”
- (Remark from Cortana in Firefight) "Radiated ballistics? What could go wrong?"
- The Fuel Rod Gun's design in Halo 2 is very similar to the ones shown in Pre-Xbox Halo.
- In Halo 2, the fuel rod gun cannot be found on multiplayer maps and cannot be used even through the game options.
- The Fuel Rod Gun is the only weapon in the trilogy which has a separate animation and timer when throwing a grenade; there is approximately a 0.5 second longer delay before you throw the grenade.
- When you give a Fuel Rod Gun to a marine, their animation is the same as if they were holding a Rocket Launcher. If you look closely, their left hand is at an angle, just like holding a Rocket Launcher.
- In Halo 2, Unggoy react very erratically upon receiving Fuel Rod Guns. When they perform their animation, one arm extends through the weapon.
- In the Halo 2 level, Regret, there is a Fuel Rod Gun hidden under a small platform in the building where you kill Regret.
- In Halo 2: Anniversary, in remastered graphics, the Fuel Rod Gun's model does not directly connect with the left supporting hand of Master Chief, resulting in the weapon looking like it's "floating" above his hand.
- In Halo PC Multiplayer, the weapon's barrel will retract into the weapon when fired. Whether this is the firing mechanism or a recoil compensator is unknown, but the weapon has very little recoil on the hands of the Spartan, supporting the latter.
- There is a discrepancy about how much the weapon actually weighs. In Halo: First Strike, Corporal Locklear had difficulty lifting the gun when he attempted to shoulder it. However, Unggoy seem to have no problem hefting the gun around in the games, so whether the situation is between the gun's weight or a comparison of Unggoy's and marines' strengths is unknown. It is strongly believed, however, that Unggoy are in fact stronger than their size lets on. Also, the model of the Fuel Rod Gun used in Halo: CE and First Strike might have been heavier than the most recent variants, or Locklear never expected it to be so heavy.
- In Halo: Combat Evolved, the Fuel Rod Gun in the game code is referred as the Plasma Cannon.
- In Halo: Combat Evolved for the PC, the wieldable Fuel Rod Gun has no idle animation.
- In Halo: Combat Evolved, the Fuel Rod Gun will explode after death of the Unggoy using it. The explosion is much like a plasma grenade explosion, only green.
- The Fuel Rod Gun was originally meant to be a grenade launcher, but it was changed to a Covenant rocket launcher. It can be viewed on this video.
- The Halo 2 level, The Arbiter, has the most Fuel Rod Guns in it of any Halo game. There are dozens of Heretic Unggoy wielding it in the Banshee portion of the level around the Forerunner Gas Mine.
- The Halo 3 level, The Covenant, has by far the most Fuel Rod Guns in Halo 3. The War Chieftain at the start wields a Fuel Rod Gun; a supply case containing a Fuel Rod Gun next to the first supply case containing a Beam Rifle; another War Chieftain at the third tower; a supply case containing a Fuel Rod Gun at the third tower on the right side; a Jiralhanae Captain protecting the first Deployable lookout tower; another protecting the second one; a crate containing two Fuel Rod Guns in a cave; a supply case containing a Fuel Rod Gun above the cave next to the plasma battery; another protecting the third one; another protecting the final one; two War Chieftains on each Scarab; and finally, two to six Fuel Rod Gun-wielding heavy Unggoy (depending on difficulty) in the Citadel.
- It appears as though the barrel and the yellow piece covering the Fuel Rod Gun retracts into the weapon when not in use. This is evidenced by the animation that plays when you switch to it. It also appears to be a recoil mechanism, and also possibly a loading mechanism similar to the slide of a handgun. The cannon fires, and the barrel and cover slam backwards, possibly dampening recoil while pulling another round from the "clip."
- The Fuel Rod Gun does not appear in standard Halo 3 multiplayer Matchmaking, as its slow-moving projectile is more susceptible to glitches and lag than other weapons. However, it is available in Custom Games and Forge.
- For whatever reason, all Firefight Voices in Halo: Reach have a saying specifically for the Fuel Rod Gun. It is referred to as "Flak Cannon" on occasion. There are very few weapon-specific sayings for other weapons, the only others being the Rocket Launcher and Plasma Launcher, probably due to their impressive power and spectacular explosions that no other weapon can match.
- In Halo: Reach, the Fuel Rod Gun appears in matchmaking, Invasion Slayer as one of the weapon drops for the Sangheili.
- In Halo: Reach, the Fuel Rod Gun has a small IR display on its left side, just above the grip, the display has its own reticle and can actually be used to aim the weapon.
- A rare glitch can occur in Halo: Reach if the gun is fired in a small room. The fuel rod will ricochet around the room uncontrollably until it hits a player or an enemy.
- It appears that the Fuel Rod Gun in the Halo: CE campaign uses a magazine, unlike the multiplayer version, which uses a battery. This is noticeable when you use Halo Map Tools to stop the gun from exploding, bump-possessing an Unggoy wielding it and walking over another Fuel Rod Gun on the floor, which will say, "Picked up 8 rounds of Fuel Rod Gun."
- In Halo: Reach, despite using only part of your ammo, it'll still show you reloading with five rounds.
- In the Halo 4 level, Requiem, there is a Fuel Rod Gun among the wreckage at the beginning of the level, but unlike the other power weapons in the area, the Sniper Rifle and the SAW, it is located in a random position near one of several dead Unggoy and isn't always present.