Grineer

"From the chaos of the Collapse, they emerged, Violent hordes of decaying clones, overflowing from their toxic womb. They flood the Origin System, swallowing colonies whole. The twin Queens, the SISTERS, have devised a plan to transform the scattered colonies into an Empire across the planets. The Sisters have sent their most trusted brood on a vital quest - the TENNO, hidden and asleep, must never awake."

- Ingame Lore Description

The Grineer are the first enemies encountered by newly reawakened Tenno. They utilize technologically crude but undeniably effective weapons. More than one Tenno has fallen because they underestimated the accuracy of a Grineer Lancer with their Grakata rifles while waiting for shields to come back up.

To a man, the Grineer are a race of clones; products of ancient, half-remembered technologies. Copies of copies, Grineer are produced in industrial quantities, and all Grineer are genetically defective, their genome damaged by the invasive cloning procedures used to birth each generation. However, these defects are as mass-produced as the Grineer themselves, allowing for the rapid standardization of techno-augmetic adaptation between such generations. Indeed, it could be argued that the Grineer are better at fixing broken bodies than they are at making ones that function to begin with. Their homeworld is a polluted, ecologically ruined Earth. They are people acting on an ultimate xenophobia, fueled by hereditary psychoses, and a burning hate of anything and anyone not like themselves. In the end, should they succeed, there will only be Grineer left alive in the solar system.

In battle, the Grineer use heavy armor coupled with attrition and ambush tactics. While they are fairly weak individually, they are a potent threat in groups, able to lay down withering streams of fire at all ranges from behind cover. Specialty troops use more advanced weapons, and many are even issued primitive, non-regenerating shields to give them an edge.

The armor on the average Grineer deserves special mention because it makes them the faction with the most resistance to Bullet damage. This coupled with several elemental resistances and the fact that the relatively common Elite Lancer is shielded makes them the most durable faction, with their Medium and Heavy units becoming absolute bullet sponges at higher levels. The prevalence of Grineer armor is also a major reason that Armor Piercing is considered the most effective element overall.

Grineer Enemies
Grineer have a dual classification system. Primarily, they are classified by their armor class - Light, Medium, and Heavy - which describe their base armor and their shared damage multipliers. Secondarily, they are classified by their role or engagement style. Infantry use rifles and shotguns and tend to find good cover and engage at medium to close range. Support use specialty weapons (ex: rocket launchers, grenades, snares, etc.) and typically engage at long range or play utility roles in combat. Finally, Brawlers engage at close range and use primarily melee weapons.

Light
Light Grineer units have no body parts protected by armor and a 1.5 bullet damage multiplier for their head.

Medium
Medium troops make up the bulk of the Grineer army. They are not particularly dangerous when alone, but in groups they can pose a serious threat. Medium Grineer share a 200 base armor, completely protected body parts, and several damage multipliers.

Heavy
These units are the strongest and toughest of the Grineer. They all have slow regenerating personal shields. Apart from the Grineer Commander, these units don't take advantage of cover. Heavy Grineer cannot seem to retaliate while under attack, showing a vulnerability to status effects; therefore it is possible to dispatch lone Heavy units easily with sustained firepower. Also, their shields will only regenerate if unbroken; once it is completely depleted, it can't be replenished. All Heavy Grineer make use of crowd controlling abilities. The Heavy Gunner, Bombard and Napalm release a short range shockwave to knock players down and backwards when first approached at close range. This ability has a long cooldown, so normal melee is possible once the shockwave has been drawn out. Commanders use Switch Teleport from a relatively long range and through cover.

Utility
The utility enemies of the Grineer are dangerous in their own right, such as the Roller, one of the most infamously annoying enemies in the game.

Captain Vor
Captain Vor is the final boss in the Mercury system and the first boss that players will meet, and also makes an appearance on Phobos alongside Lieutenant Lech Kril as a dual boss battle. He can be found in the mission Tolstoj on Mercury and lliad on Phobos. He drops the Cronus blueprints on death, but as of Update 9 he will also have a chance to drop parts to the Seer Pistol upon death. He also drops Morphics.

Councilor Vay Hek
Councilor Vay Hek is the final boss in the Earth system. He is found at Everest. He has a chance of dropping one of the following on death: Trinity Helmet, Trinity Chassis, Trinity Systems blueprints, as well as Neurodes, and Orokin Cells.

General Sargas Ruk
General Sargas Ruk is the final boss of the Saturn system. He can be found on Tethys. He has a possibility of dropping one of the following on death: Ember Helmet, Ember Chassis and Ember Systems blueprints, and the Orokin Cell.

Kela De Thaym
Kela De Thaym is the boss of Sedna. She can be found on '''Merrow. ''' She has a possibility of dropping one of the following on death: Saryn Helmet, Saryn Chassis or Saryn Systems blueprints.

Lieutenant Lech Kril
Lieutenant Lech Kril is the final boss of Ceres, and also makes an appearance on Phobos alongside Captain Vor as a dual boss battle on the planet. He can be found on the mission Exta on Ceres and lliad on Phobos. He has a possibility of dropping one of the following upon death: Frost Helmet, Frost Chassis and Frost Systems blueprints, as well as the Orokin Cell.

Tyl Regor
Tyl Regor is the final boss of the Uranus system. He can be found on Titania. He has a possibility of dropping one of the following on death: Ash Helmet, Ash Chassis and Ash Systems blueprints, as well as Gallium.