Metal Gear Solid: Snake Eater 3D released this week on 3DS, and its story serves as the beginning of the entire MGS saga. Nintendo fans have only gotten a look at one other Metal Gear model, in The Twin Snakes. For fun, and to give some indication of how complex the plotline is in the MGS series, I’ve written this piece, which details the main Metal Gear archetypes across all the MGS games. This list is not exhaustive. For example, Metal Gear RAXA and Metal Gear ZEKE—both from the PSP games—are not included below, and neither are the original Metal Gear or its successor, Metal Gear D.

The Shagohod

Surprisingly, the MGS series does not begin with a Metal Gear-type weapon. All Metal Gears are essentially bipedal tanks, and most of them are nuclear-capable. The Shagohod, designed by Soviet engineer Aleksandr Leonovitch Granin, was built by Nikolai Sokolov under the thumb of Colonel Yevgeny Volgin. Interestingly, Granin also drew up plans for a weapon that would later become Metal Gear REX. The Shagohod’s purpose is to launch nuclear-capable IRBMs (intermediate-range ballistic missiles) without the need for a rocket. The Shagohod is propelled via Archimedes’ screws for normal movement, but the rear compartment houses immense rocket boosters, allowing the Shagohod to build up considerable speed before launching its IRBM, which then has a range of some 6,000 miles. The Shagohod is also outfitted with machine guns, a volley gun, and surface-to-air missiles to stave off enemy forces in combat zones.

Despite its considerably capabilities, the Shagohod is gimped by a number of factors: in order to be effective as an IRBM launcher, the Shagohod must have an enormous amount of flat land to achieve the proper acceleration. Additionally, since the Archimedes’ screws are its only normal movement method, damage to those screws renders the tank immobile. Naked Snake and EVA eventually destroy the Shagohod, which left no descendants in the MGS series.

Metal Gear REX

Revolver Ocelot, working for the CIA, stole Granin’s Metal Gear drawings. Developed in secrecy at Shadow Moses Island in Alaska*, Metal Gear REX was backed by DARPA and built by weapons firm ArmsTech. Hal “Otocon” Emmerich designed the mech, believing it would be used as an anti-nuclear weapon. REX has impressive specs: capable of walking over a variety of terrain types thanks to its bipedal legs, it is heavily armored and fully enclosed. It sports two 30 mm Vulcan canons, an electron laser, and anti-tank missiles to protect itself in combat zones.

REX’s primary purpose, however, is to use a magnetic railgun to launch untraceable nuclear missiles to any target in the world. Unfortunately, a design decision ultimately crippled the mech: as it is fully enclosed, REX’s pilot relies on information gathered from a large radome—a satellite-shaped object on REX’s left side—to drive the vehicle and attack targets. Damaging the radome forces the pilot to open the cockpit and drive unprotected. Despite being heavily damaged during the Shadow Moses Incident, REX was able to battle the technologically more advanced Metal Gear RAY to a standstill decades later.

*There is no such island. However, the archipelago that Shadow Moses is supposedly a part of—the Fox Islands—are real.

Metal Gear RAY

Years after the Shadow Moses Incident, REX variants began cropping up around the world, as that mech’s plans were leaked to the black market by Revolver Ocelot. The U.S. Navy built its own Metal Gear RAY as a sort of anti-REX weapon. RAY is larger, submersible, and includes a number of advanced weapons, including a high-pressure water jet cutter. Whereas REX was powered entirely through pneumatics and hydraulics, RAY was built with sophisticated muscle-fiber-like technology in order to make it even more maneuverable. Additionally, armor-patching black paste fills areas between cracks in the false muscle or armor, looking a bit like blood. RAY also originally had a long tail for balance while running and swimming. The Navy’s version is a manned prototype, and was stolen by Revolver Ocelot at the beginning of MGS2. Years later, RAY reappeared in an unmanned, AI-controlled form. This new RAY was sleeker in design (the tail section is missing, for one), mass-produced, and used to defend Solidus Snake’s powerful Arsenal Gear submersible. In addition to its water cannon, RAY is equipped with Gatling guns and missile launchers. Unlike its predecessor, RAY was never meant to be nuclear-capable.

Liquid Ocelot further modified RAY during his attempted hostile takeover of the Patriots. These new RAY units protect his Outer Haven fortress (a stolen and modified Arsenal Gear). They do not differ significantly from their Arsenal counterparts, and in fact show a few features of the original Navy design. Despite its pedigree, the new RAY units are unable to destroy the prototype Metal Gear REX on Shadow Moses Island.

Arsenal Gear/Outer Haven

The Shagohod, Metal Gear REX, and Metal Gear RAY are all designed to be conventional weapons of warfare; Arsenal Gear was built to wage information warfare on the world. The number of Arsenal Gear units is unknown, but Solidus Snake took control of one in the events of MGS2, and Liquid Ocelot commandeered another during MGS4. Arsenal Gear houses one of the Patriot AI’s, GW (“George Washington”), which has the ability to track and censor global Internet information. Its purpose is to keep hidden any information the Patriots are unwilling to share with the world. It can modify, block, and tamper with digital information. Additionally, Arsenal Gear has complete control over the military’s tactical network—giving the Patriots complete control over the United States’ armed services. Arsenal Gear also carries a payload of nuclear weapons. To protect itself, Arsenal Gear is equipped with an army of 25 mass-produced Metal Gear RAY’s, a legion of military personnel, missiles, and of course, its nuclear payload.

Solidus’ Arsenal Gear was deactivated by a computer virus and crashed headlong into New York City. Sometime after this, the Patriots constructed an improved Arsenal Gear that doubled as a battleship. Liquid Ocelot, having recovered what he could of GW’s components, stole one of these battleships, renamed it “Outer Haven,” and used it to rebuild GW with the intention of destroying the Patriot’s “main” AI core, JD. At that point, Patriot control would secede to GW, giving Liquid Ocelot control of the entire Patriot network. Solid Snake, with some help, managed to sneak into GW’s mainframe and upload a new virus that destroyed not only it but the other Patriot AI’s as well. As with Arsenal Gear, an army of modified Metal Gear RAY units, hundreds of Metal Gear GEKKO variants, Liquid’s considerable PMC, and numerous security measures similarly protect Outer Haven.