The mechanics of the Arm Cannon.

Samus Aran's Arm Cannon is her primary weapon, capable of both shooting energy-based beam attacks and ballistic Missiles. The Arm Cannon, as its name implies, is affixed to the Power Suit's right forearm.


What separates the Arm Cannon from other firearms is its ability to access various weapons systems by quickly changing its configuration, thus eliminating the need for multiple (and sometimes bulky) guns such as weapons mounted on the Federation Force's Mechs and Anthony Higgs' Plasma Gun. For example, during her mission on Tallon IV, Samus could switch between four beam systems (excluding the Phazon Beam), Missiles, and four Charge Combos for the beams. Despite its complexity, the Arm Cannon in Metroid Prime 3: Corruption and all games in the 2D Metroid series is unable to switch between the beams collected throughout the course of the game. Instead, they stack, resulting in a Power Beam that gains more power and new attributes as more beams get added. By default, Samus' Arm Cannon always features the Power Beam.

Interestingly, much of the technology Samus Aran uses, including her Map and Metroid Detector, seems to be mounted along the Arm Cannon as suggested by various cutscenes in Metroid Prime and Metroid: Samus Returns.

In addition to beams and missiles, the Arm Cannon can also be used as a melee weapon as shown in Metroid: Samus Returns and Metroid Dread via the Melee Counter during which Samus swings her Arm Cannon.

Physical description[]

The Arm Cannon in Metroid Prime.

The Arm Cannon in Metroid Prime 3: Corruption.

In the Prime series, the Arm Cannon features many different configurations. The standard configuration, where the Cannon appears completely smooth, always represents the Power Beam. The wide configuration, where the sides of the Cannon expand, is used for the Wave, Light, and Nova Beams. The high configuration, where the top and bottom pieces of the Cannon move vertically, is used for the Ice Beam, Dark Beam, and Ghor's version of the Plasma Beam (though the Plasma Beam is only in this configuration in Metroid Prime 3: Corruption.) The long configuration, where the muzzle of the Cannon extends forward, is used for the Plasma Beam (only in Metroid Prime) and the Annihilator Beam. A fifth configuration, only seen in Corruption when Samus enters Hypermode, shows the Cannon opening up in apparently the wide configuration, but with half-pipe like chutes on the sides, presumably for ventilation. In Prime, the Phazon Beam expands the gun in all directions at once. The last configuration, where four parts of the Arm Cannon protrude in four directions, the tip of the Cannon contracts and turns blue, and a ring separates from the Arm Cannon and widens, is used only for the Zero Laser. In Metroid Prime Hunters, the Arm Cannon's configuration is not changed, however, the lights of the cannon do change color when using Affinity Weapons.

The Arm Cannon is also shown to have many other functions, such as uplinking with computers or other systems, welding, melee combat, and controlling Samus' Gunship. In the Prime series, it is occasionally shown to have colored buttons on the inside of the left round section when it flips open (this may represent the canonical way Samus changes beams). The Arm Cannon can also be picked up and thrown by smashers in Super Smash Bros. Brawl when Samus sheds her Power Suit as part of the three pieces it leaves behind. The Arm Cannon's three rings are shock absorbers to deal with recoil.

The Arm Cannon's appearance in Metroid Fusion greatly differs from previous models.

In Metroid: Other M, the exterior of the Arm Cannon has two green circles. In Samus Returns and Metroid Dread, there are glowing patterns on the arm that change color depending on the beam equipped, matching them.

The inside of the Arm Cannon is more simplistic and is simply a long, narrow tube with some sort of trigger mechanism at the end, into which Samus inserts her hand. It can only be seen when using the X-Ray Visor because other visors cannot look through the solid Arm Cannon. The opening scene for Metroid: Other M shows what the inside of the arm cannon's barrel looks like and what happens when a beam is fired, and Metroid Prime Trilogy shows another, alternative look during the start-up video and through to the Samus Data Screen.

Arm Cannon weapon systems[]

The Arm Cannon is shown to assimilate weapons from multiple species including the Chozo (who designed the cannon), Alimbics, Luminoth, Phrygisians, unknown species, Space Pirates, and, to a lesser extent, the Galactic Federation. Below is a list of these weapons.

Beam weapons[]

Concept art of several Beams for the Arm Cannon from Corruption.

Ballistic systems[]

Fusion Suit arm cannon Missile configuration.

Charge Combos[]


Use by individuals other than Samus Aran[]

Though Samus's Arm Cannon is of Chozo design, other species (as seen in Metroid Prime Hunters) have created their own arm cannons with identical functions, some likely inspired by the bird race's. After the malevolent Gorea steals the six Affinity Weapons from their respective Bounty Hunters, it manifests two organic arm cannons in order to use the weapons on Samus during the first phase of the boss battle between the two. Gorea can also swipe at Samus with these arms if she comes too close.

Dark Samus uses an organic version of the Chozo's Arm Cannon, created from Metroid Prime's essence fusing with Samus's Phazon Suit; it can fire many of her weapons, with a few being Phazon-based. Largely thanks to it being an X-Parasite born from infecting Samus's power suit, the SA-X was also shown wielding the Arm Cannon, also having access to its full weaponry, notably including the Ice Beam. It also spawned multiple versions of the Arm Cannon when mutating during its final encounter with Samus Aran, although it was left unclear whether they were usable due to the mutated SA-X preferring to pounce on her.

The violent leader of the Mawkin tribe of the Chozo, Raven Beak, uses an Arm Cannon as one of his main weapons. He notably used it to kill the surviving Chozo of the Thoha tribe, as first seen in the final image of the Chozo Memories in Metroid: Samus Returns. He later uses the Arm Cannon during both of his fights with Samus during Metroid Dread. During their first encounter in the game's opening, Raven Beak uses it to obliterate the entrance to a large Chozo monument right behind her and later prepares to shoot Samus point-blank after placing her in a neck-lift. The Mawkin Robot Chozo Soldiers use Arm Cannons as well. A flashback in the scene just before the final battle with Raven Beak indicates that the reason Samus is able to use her arm cannon was because she was infused with his Mawkin genes. One of the Chozo Archives also implies that Raven Beak's arm cannon was potent enough in terms of firepower to effortlessly leave an E.M.M.I. severely damaged.

Official data[]

Logbook entry[]

Arm Cannon

Metroid Prime Hunters

Logbook entry

An essential part of SAMUS's POWER SUIT, the ARM CANNON is UPGRADABLE and adaptable to other weaponry. To fire the weapon, press the FIRE button, Switch weapons by tapping the weapon icons at the top of the touch screen.

Official Metroid Prime website[]

The Arm Cannon as it appeared in the Metroid Prime beta.

"Weapon effect: Devastating potential

Weapon range: 3-10 m

Weapon potential: Lethal

The Arm Cannon is Samus Aran's primary offensive weapon. Built into the right arm of the Power Suit, the Arm Cannon is upgradeable with a variety of weapons, including the Wave Beam, Ice Beam, and others. When used in combination with secondary weapons such as missiles, the Arm Cannon can become a devastating offensive tool."

Nintendo Power issue 162, page 37[]

"Unlike many first-person titles that require you to exchange one weapon for another, all of Samus's attacks are contained in one compact unit: the Arm Cannon.
The Arm Cannon can switch from one weapon to the next with a simple flick of the C Stick. In the scene above, Samus is attacking an enemy with the Wave Beam.
Another Arm Cannon upgrade is the Ice Beam, which freezes some enemies solid with a single blast and eliminates some others."

Metroid Dread Report Volume 5[]

"Samus’ right arm is completely integrated with her powerful and iconic Arm Cannon, which can fire two types of weapon: rapid-fire beam attacks and powerful missiles. Because the Arm Cannon is so deeply integrated, Samus can toggle between weapon classes at will.

In the Metroid Dread game, you can attack from nearly any angle while running, jumping, or holding on to certain walls and ledges."

Beam Attacks
"The beam attack is Samus’ go-to offensive ability. Acquiring upgrades can modify its power and properties, like increasing the attack’s spread or adding other functions."
"One such functional upgrade is the Grapple Beam, which lends it a rope-like quality that makes the Arm Cannon capable of connecting to specific points. Once connected, Samus can tow objects or swing herself to otherwise unreachable parts of the environment."
"Unlike the endless wave of beam blasts at her disposal, Samus has a capacity limit for this compact yet powerful heavy weapon. It, too, can be enhanced with ability upgrades. Samus can increase her missile capacity—thus being able to hold more—by acquiring Missile Tanks and Missile+ Tanks scattered throughout the world. Search with diligence!"
~Transmission from the Dev Team~
"Each attack can be done while running or jumping. In the Metroid: Samus Returns game for the Nintendo 3DS™ system, Samus had to plant her feet to Free Aim and fire—now, you can aim forward in a wide range of angles while running. This makes it easier to attack from a distance while on the move.
In the Metroid Dread game, most actions—like Arm Cannon attacks and Melee Counters— can be performed from nearly any position. We wished to emphasize the player being able to maintain their speed and momentum at any given time, aiming to make the flow through different types of gameplay feel as seamless as possible."

Nintendo tweets[]

Nintendo of America
"Samus' Arm Cannon can switch between two weapons at will: a beam that can be fired in rapid succession, and powerful missiles.
In #MetroidDread, you can freely shoot at various angles while running, jumping, or holding onto walls."[2]
Nintendo of Europe
"Samus’ trusty Arm Cannon is her go-to weapon when dispatching enemies. She can use it to shoot rapid-fire Beam blasts or powerful Missiles from various angles, even when she’s running or jumping. #MetroidDread"[3]


Samus cycles through beams in Metroid Prime.

Samus fires the Arm Cannon in Metroid Prime 3: Corruption.

Samus' hand can be briefly seen inside her cannon when changing beams in Metroid Prime.

  • A common misconception among new fans of the Metroid series, as with Samus's gender and name, is that the Arm Cannon is a prosthetic arm for Samus, who in reality has not lost her right arm. Later games have made efforts to dispel this myth further by showing Samus's right hand in one way or another, either by showing her wearing the Zero Suit, which frees both of her hands to grab onto ledges, or by showing her right hand inside the cannon via an X-Ray Visor.
    • In addition, the first issue of Dark Horse Comics' adaptation of Metroid Prime depicted in one of the first panels an otherwise fully suited Samus putting her helmet on and specifically wearing both gloves, further reinforcing that her right arm was not prosthetic and that the arm cannon was merely an add-on.[4]
  • The Arm Cannon is an unlockable weapon in Phantasy Star Ø for the Nintendo DS; It is also an unlockable weapon in Monster Hunter 4 Ultimate, along with two armor sets based on the Power Suit and Zero Suit
  • The X-Ray Visor, when activated, allows Samus's hand inside the Arm Cannon to be seen. In Metroid Prime, Samus uses her hand to change configurations by changing her finger positions, which match the symbols featured in Beam Select. In Metroid Prime 3: Corruption, Samus can be seen pulling some kind of trigger with her index finger to fire.
  • In Corruption, after performing some interface while equipped with only the Power Beam, the Arm Cannon will seemingly "phase out" but will return to its original position shortly.
  • In Corruption, the Arm Cannon is the only part of Samus's suit that does not get recolored by Phazon as her corruption progresses. The Arm Cannon only ever shows signs of Phazon changes when using Hypermode.
  • As seen in the first Concept Gallery, the Metroid Prime Wave Beam configuration was initially intended for the Plasma Beam, and vice-versa.
  • In Prime, if Samus is idle and waits long enough she will flip a panel with four lights that show the colors of the game's four beams. This can occur even before she obtains three of these four beams.
    • The same animation reappears in Echoes, where when Samus is idle, she will flip a panel with three lights that show the colors of three of the four beams in game, even before the others are obtained (although the Annihilator Beam combines both dark energy and light energy, making the colors for the Dark Beam and Light Beam universal for the beam).
  • In New Play Control! Metroid Prime and Metroid Prime Trilogy, it is possible to see Samus's hand when she changes beams while pointing the cannon upwards.
  • In many Prime cutscenes, the Arm Cannon is revealed to be rifled on the inside. This makes little sense, as all of her Beams are energy-based (rifling is used to give a spin to bullets/grenades in order to make them fly straight). It may be used for her Missiles, but these do not require rifling either. Missiles have small wings to keep them flying straight (or guiding them while homing), although Super Missiles are bulb-shaped and do not have wings in some of the games.
    • The Arm Cannon rifling would make sense to be used in Metroid Prime Hunters on the other hand, as the Battlehammer and Magmaul are shown to have projectiles arcing before impacting.
  • The Melee Counter in Samus Returns is the first time outside of the Super Smash Bros. series that Samus is depicted using her Arm Cannon as a melee weapon.
  • The Arm Cannon has been released as a licensed replica.
  • Concept art for Meta Ridley in the Metroid Prime Trilogy art booklet has him wielding a similar weapon to Samus's Arm Cannon on his left arm, implying that his cybernetics were to incorporate Chozo technology.
  • The Arm Cannon is depicted as a wrist-mounted accessory similar to a diving harpoon gun in both the 1990 and 1991 versions of The Power Game Calendar. Bayonetta's rendition of the Power Suit in Bayonetta 2 also depicts it with a similar wrist-based design.
  • In Metroid Dread, the tip of Samus's Arm Cannon glows when she fires her weaponry, before rapidly cooling.[5]


References and footnotes[]

  1. ^ a b In the Prime series, Super Missile is used as a Charge Combo that simply drains five Missiles per shot. In most 2D games, the Super Missile is a separate weapon with its own ammo much like the Power Bomb. In Metroid Fusion and Metroid Dread, it overwrites the original Missile data and increases its power.
  2. ^ Nintendo of America (NintendoAmerica). 20 August 2021 2:30 p.m. Tweet.
  3. ^ Nintendo of Europe (NintendoEurope). 22 August 2021 6:00 a.m. Tweet.
  4. ^ sc_164pg01-02.jpg (840×583) (
  5. ^ Looygi Bros. "15 Cool Details in Metroid Dread (Part 3)" YouTube. December 17, 2021. Retrieved December 18, 2021.