Factions

There are currently four distinct factions in Warframe. While it is never outright stated, every known faction appears to be (or have once been) human. The only playable faction are the Tenno; the Grineer, Corpus, and Infested factions are presented as adversaries.

Grineer
"Vast in numbers, the Grineer have expanded their vile empire from Earth outward to all sectors of the solar system. Once the Grineer rediscovered cloning technology, they seized control of Earth through sheer numbers. While they may be at the height of power, the Grineer army is in bodily decay and their features are increasingly primitive as a result of continuous cloning. As such, the Grineer are forced to use technology as a crutch for their genetic deterioration. An ideology of hate and discrimination towards the Tenno continues to drive the Grineer forward in the face of inevitable dissolution."

- Warframe Official Website

Additional Information

The Grineer are the first faction the player encounters, and the first enemies fought. They use cloned marines as their basic infantry, occasionally having more powerful variants.

Corpus
"The Corpus are a dominating proto-corporation of humans that maintain and operate the trade routes of the Solar Rails. They are rarely seen by others and are better known for the robot proxies that serve for them. The social structure of the Corpus is said to reflect ancient mercantile guilds from the Old Earth. Their production methods blend technology and ritual, in-part, because the ancient Orokin materials they use are inscrutable to them. They control the entire supply chain of goods that flow through the solar system. The Corpus view Orokin artifacts as resource to be exploited for profit− at any cost."

- Warframe Official Website

Additional Information

The Corpus are one of the enemies encountered after the Grineer, and operate differently. They tend to use robotic walkers called 'Moas' and Crewmembers as their basic infantry, but also employ stationary turrets and cameras. They also make use of various drones, which can perform various actions such as laying mines or shielding nearby Corpus.

Infested
The Infested are what appear to be humans who have been taken over by some sort of virus or parasite. The majority of Infested seem to be former Corpus Crewmen or Grineer Lancers. However they are also speculated to originate from failed Tenno experiments, hinted at by J3-Golem asking the Tenno, "Why do you destroy us, we are your flesh", yet, have also been hinted at by several references to a "Technocyte Virus" in some missions. Most Infested do not have any significant ranged combat ability. t

Tenno
"The Tenno are descendants of an ancient and mystical civilization of lost warriors from the Orokin era on Earth. Preserved in cryopods for centuries, the Tenno now awaken to a new war, fighting and resisting warring factions as the sole bearers of the Orokin-created Warframes.  While the memories of the Tenno have faded over time, their mastery of guns, blades, and Warframe exo-armor has not. Fragments of history suggest that discipline and chivalry are the cornerstone values of the Tenno: is this true today? The Tenno are emerging into a world unfamiliar to them. One sees a noble warrior, building his strength against an oppressive regime. Another sees an opportunistic mercenary, exploiting the Warframe's superiority for wealth. Regardless of their future, the Tenno stand united against a common foe, loyal only to each other."

- Warframe Official Website

Additional Information

The Tenno are the faction controlled by the players. Each player is a Tenno wearing a suit of armor called a Warframe. The Warframes' combat abilities are vastly superior to both the Corpus' high technology and the Grineer's vast numbers; even the most inexperienced Tenno can fight their way through hordes of basic foot soldiers alone, and teams of experienced Tenno can best even the deadliest enemy threats.

Awakening from deep slumber to a hostile world, the Tenno know little of themselves. They appear human, but the mysterious nature of ancient Warframe technology leaves open the possibility that they have undergone extensive genetic or biomechanical enhancements to stay on the edge of progress like the Grineer, or that such modifications may be required to to use their Warframes in the first place. As the Tenno are never seen outside of their armor, even partially, it's impossible to know.

Each Warframe bears one rifle, one sidearm, and a melee weapon. Their arsenal includes rifles of various types, shotguns, pistols, swords, and more exotic close range weapons like staves, axes, and power gauntlets. Different classes of Warframes offer their own unique powers, ranging from Volt's burst of superhuman agility to Frost's deadly avalanche, and the armor's modular nature allows for major upgrades and wide customization options. Solitary squads in the field have adapted to wildly different situations using only a moment of downtime between missions.

Upon revival from their cryostasis, Tenno take guidance from a figure who simply calls herself Lotus. Asserting preservation of her people by any means necessary, she dispatches and guides Tenno through missions of espionage, sabotage, defense, slaughter, and rescue, but only with audio commands from an unknown location. Like the rest of Tenno culture, she remains shrouded in mystery.

Speculation

The Tenno are mysterious in the extreme, with most of the details about their lives, origins, and motives unknown. Given this uncertainty, speculation surrounds many aspects of the Tenno.

One such aspect is the gender of individual Tenno. In-game text labels the Warframes themselves as having genders. Certain frames have obviously male or female features and are referred to as such in the text, which begs the question of how a Tenno can, for example, change from the bulky, masculine Rhino to the slight, feminine Mag. Explanations abound for this oddity; one hypothesis is that the Tenno are genderless themselves, and simply appear male or female depending on the armor they wear. It is also possible that Warframes aren't really a suit to be worn, but rather a sort of artificial proxy body controlled remotely by a Tenno operator, or perhaps even that Tenno are not bound to physical bodies and may freely move their consciousness to whichever Warframe body suits them. Although less fantastic, another theory is that there are not actually thousands of individual Tenno as represented by the number of players in the game. Instead, each "class" of Warframe actually represents an individual Tenno rather than a variety of armor, and in reality there are only twelve Tenno in existence (one for each Warframe).