"Sera's dying, Marcus—the whole planet's infected. It's the Imulsion that's killing it. It was always the Imulsion, you see, and I can stop it."
Adam Jonathon Fenix[1]

Imulsion was a luminescent, highly volatile, low-viscosity fluid originally discovered by an oil exploration drill on the planet Sera. The discovery of the substance and its use as a fuel played a key role in Seran and Locust history. Control of Imulsion was the main cause of the Pendulum Wars, which weakened humanity's unity but gave them the strength to fight the Locust Horde on Emergence Day.[2]

During the Lambent Pandemic, Adam Fenix determined that Imulsion was actually a living parasite feeding off other beings, including humans. Adam's failure to provide Queen Myrrah with a solution to stop Lambency and the Lambent War resulted in the Locust's distrust of humanity and the Locust War. In 17 A.E., Imulsion and its resulting Lambent lifeforms were destroyed by Adam with the Imulsion Countermeasure Weapon.[3]


Discovery and Pendulum WarsEdit

"Well, in a few words: Imulsion is a newly-discovered fuel source that may render Sera's energy crisis non-existent. Cheap and limitless, Imulsion may be the answer to all of Sera's fuel problems."
—An unknown scientist explaining Imulsion's potential as a fuel source.
Pendulum war

Soon after Imulsion turned into fuel, the COG and UIR fought over it.

The substance known as Imulsion was considered to be more of a scientific curiosity than a practical resource after its discovery, and was essentially useless until Dr. Helen Cooper created the Lightmass Process. The process was capable of refining Imulsion into an efficient energy source.[4] For a planet hungry for energy and facing something of an energy crisis in the long term, Imulsion was the perfect solution: efficient, clean and fairly abundant.

As Imulsion extraction and conversion began to pick up steam, a certain few nations reaped huge rewards from its sale, while other less fortunate ones were denied the profits. Over time, Imulsion speculation on the financial markets ran rampant and entire currencies and economies became linked to its value. This eventually resulted in a large economic collapse on the planet Sera when extremely low Imulsion prices crippled the financial sector. The economic crisis sparked military actions, and the few countries that possessed an abundance of Imulsion reserves soon found themselves at war with those nations who were not as fortunate, in a conflict known as the Pendulum Wars.[5]

Health CrisisEdit

Unknown to most of the public during this crisis, a new one was forming as miners of Imulsion and their families were becoming sick with a new disease known as Rustlung, caused by prolonged exposure to Imulsion fumes. The nations that held the majority of Imulsion reserves, known as the Coalition of Ordered Governments, relocated the infected to the New Hope Research Facility so that their existence would be shielded, but to also find a cure. Director Niles Samson used genetic experimentation to attempt at a cure, but instead resulted in mutated humans known as Sires, and their children born with deformities who would later be regarded as Locust. Due to attacks on the staff and information leaks, Chairman Monroe ordered the shutdown of the facility and relocate the children to the underground of Mount Kadar.

As the Pendulum Wars raged on the surface for the next 79 years, the Locust became organized and developed civilization in the underground city of Nexus. However, the Locust then began to face the same troubles as their parents when members of the Locust became infected with Lambency, when Rustlung advances and Imulsion colonizes every cell in the body, forcing the host to infect all forms of life around it. The Locust then became engaged in a civil war with their infected brethren. Queen Myrrah suggested that they abandon the Hollow and colonize the surface, killing all humans to do so. However, she first sought the assistance of human scientist Adam Fenix to find a cure for Lambency. But the Lambency simply evolved past any biological solution, and any other solution would harm the Locust due to their genetic material. When Adam was unable to find a cure for Lambency, Myrrah pushed for her people to invade the surface.

Locust WarEdit

After 79 years of fighting, the Coalition won the Pendulum Wars against the Union of Independent Republics. Six weeks after their victory, however, the Locust emerged and began a genocidal campaign until humans went extinct. Within the initial attack, 25% of Sera's population was killed. The humans were pushed back to cities located on the Jacinto Plateau, namely Ephyra and Jacinto City. Meanwhile, the humans continue to mine Imulsion using derricks, as the Hollow was occupied by the Locust, who also used Imulsion as a source. By 14 A.E., the COG developed a Lightmass Bomb and a Sonic Resonator. By using the resonator, they would map the Locust tunnels, and then send the Lightmass Bomb to destroy them. The Lightmass Bomb was successfully deployed during the Lightmass Offensive. However, the heat from the bomb caused the Imulsion in the Outer Hollows to evaporate, exposing the remainder of humanity to Imulsion fumes and causing a new wave of Rustlung.

Six months after the Lightmass Bombing, the Locust were preparing to sink Jacinto as they did with Tollen, Montevado, and Ilima, using the gigantic Rift Worm that had been awakened by the Lightmass Bomb. The COG then deployed Operation: Hollow Storm, sending a majority of their forces underground to defeat the Locust once and for all. The Rift Worm was destroyed, and the COG then discovered the Civil War between the Locust and Lambent as the reason for the Locust invading the surface. The COG then discovered a recording from Adam Fenix detailing that sinking Jacinto would flood the entire Hollow with seawater, drowning anything underground. Jacinto was then sunk by the COG when a Brumak became infected with Lambency and was detonated by the Hammer of Dawn. The city fell and the walls of the plateau collapsed with seawater, drowning a majority of the Locust. The COG then eventually relocated to the island of Vectes.

Lambent PandemicEdit

Despite a conflict with the Stranded on the island of Vectes, the COG had momentarily found some peace. But by 15 A.E., the Imulsion quickly polluted Sera's oceans and landscapes, giving rise to new and more aggressive Lambent lifeforms, among them the Lambent Stalks, Lambent Leviathans, and Polyps. The Lambent began to sink ships and invade inland, killing and infecting everything in their path. Meanwhile, Adam Fenix, who had been kidnapped in 10 A.E. by Chairman Richard Prescott, was situated in Azura, a secret COG facility, taking samples from the Vectes attacks and developing a solution for the Lambent Pandemic, a targeted radiation pulse-wave that would only kill cells infected with Imulsion, otherwise known as the Imulsion Countermeasure Weapon. Prescott then abandoned the COG to bring more samples for Adam and help develop the weapon, as Sera had a few years left before the entire planet became infected. Adam then began injecting himself with Imulsion in order to study its lifespan and reproduction, to ensure the countermeasure would work.

By 17 A.E., the weapon was completed, but Azura was invaded and captured by the Locust, with Adam left alive and Prescott escaped to find reinforcements. The COG had since been disbanded, but reorganized to take back Azura and activate the countermeasure. By that time, humans began becoming Lambent along with all other species on the planet, as the Imulsion reaches a critical stage in its life cycle. Adam detonated the countermeasure, which resulted in the death of Adam Fenix, Imulsion, and any life-form heavily colonized by Imulsion while those less infected were cured of their affliction.


Though Imulsion and the Lambent were destroyed by the weapon, the Locust were not killed but instead triggered a mutation where all Locust life-forms were cocooned in a crystalline shell, where they evolved until 42 A.E. into the Swarm. Over the next twenty-five years a technological dark age would define the civilization that was attempting to rebuild itself. Humans were forced to return to and consult traditional and alternative energy sources in the hopes of restoring the Seran society that had existed during the Era of Silence. Due to the ingenuity of Damon Baird, the newly reformed COG turned to automation and fabricators to rebuild civilization.

Known Areas with ImulsionEdit

Known Imulsion Fields/Facilities/PlatformsEdit

Mining MethodsEdit

Old oil rigs and Derricks were repurposed to extract Imulsion from pockets near the surface. Facilities like Lethia Imulsion Factory and the Denava Imulsion extraction facilities mined deep into the Outer Hollow, and Imulsion crystals were used for military purposes.[9] Offshore Imulsion deposits required advanced drilling platforms in order to be tapped.


Raw Imulsion

Imulsion in its raw state.

Besides its nature as a valuable energy source when properly processed, Imulsion also possessed a fascinating mutagenic effect. Direct exposure to Imulsion for any length of time could cause almost anything to transform into a Lambent form, making them highly aggressive, bio-luminescent and highly explosive when killed. In extreme cases, Imulsion exposure will cause the subject to mutate uncontrollably, such as the Lambent Brumak.[10]

On the death of a mutated subject that does not result in explosion, the Imulsion was seen to escape the host body and move on its own.[11]

Prolonged exposure to Imulsion, particularly in an aerosol form, was known to cause health problems in humans, chiefly the respiratory disorder called Rust Lung; Gold Rush miners had a shorter life span than the average human and many became infected.

As refined Lightmass, Imulsion was credited as being far cleaner burning and more efficient than traditional gasoline. When utilized in a generator, burned Lightmass would emit a yellowish exhaust.

Adam Fenix revealed that Imulsion was actually a living parasitic organism that mutated its host. He believed that Imulsion had properties of fungus and that the Lambent Stalks were actually Imulsion's fruiting bodies.

Behind the scenesEdit


Like "no blood for oil," Tyrus has an anti-war movement

  • In Campaign and Multiplayer, propaganda posters can be seen on walls: a picture of an upraised hand with the phrase No Blood for Imulsion. This suggests that the campus population opposed the Pendulum Wars on that basis. The phrase is also a play on the anti-war slogan "No Blood for Oil" popularized by the opposition to the 1991 liberation of Kuwait from Iraq. To find it in Gridlock, you can look by one of the spawn points right against a brick wall.
  • While petroleum exists in the Gears of War Universe, Imulsion serves as an allegory to oil throughout the series. Much of the infrastructure around the exploration, extraction, refinement, shipping, distribution, and utilization of Imulsion is similar to that of the petrochemical industry.

See alsoEdit


  1. Gears of War 3: Act I: Anchored
  2. Gears of War: Destroyed Beauty
  3. Gears of War 3
  4. Destroyed Beauty - An Inside Look at Gears of War, page 3
  5. Destroyed Beauty - An Inside Look at Gears of War, page 4
  6. Gears of War: Anvil Gate
  7. Gears of War
  8. Gears of War: Unsaid
  9. Gears of War: Aspho Fields
  10. Gears of War 2
  11. Evidenced by cutscenes in Act 4 of Gears of War 2
Enemy Types
Locust Horde
Queen · Sire
Berserker (Matriarch) · Boomer (Butcher, Flame Boomer, Grinder, Mauler, Mauler Elite, Savage Boomer, Tremor) · Drone (Beast Rider, Bolter, Cleaver Theron, Cyclops, Flame Drone, Flame Grenadier, Grappler, Grenadier, Grenadier Elite, Gunner, Hunter, Hunter Elite, Miner, Palace Guard, Savage Drone, Savage Grenadier, Savage Grenadier Elite, Savage Hunter, Savage Marauder, Savage Theron, Sniper, Spotter, Theron Elite, Theron Guard, Theron Sentinel) · Kantus (Armored Kantus, Savage Kantus) · Rager
Hollow Creatures
Bloodmount · Brumak · Corpser (Shibboleth) · Digger · Gas Barge · Heart Leech · Kraken · Kryll · Leviathan · Mangler · Nemacyst (Ink Grenade) · Nemacyte · Reaver (Assault Barque · Hydra) · Riftworm · Rockworm · Seeder · Serapede · Siegebeast · Tempest (Shrieker) · Ticker · Torture Barge · Wretch
Former · Lambent Berserker · Lambent Brumak · Lambent Drone (Lambent Drudge) · Lambent Gunker · Lambent Leviathan · Lambent Polyp · Lambent Stalk · Lambent Wretch
Canker · Carrier · DeeBees (Bastion · Reject · Stump) · Drone (Elite Drone · Grenadier · Elite Grenadier · Hunter · Elite Hunter · Imago · Sniper · Elite Sniper) · Flock (Leech) · Hive Beast · Juvie (Screamer · Popper) · Kraken · Locust Drone · Matriarch · Pouncer · Scion (Speaker · Warden) · Sire · Snatcher · Swarmak
DR-1 · Shepherd (Deadeye) · Tracker (Shock Tracker) · Watcher (Guardian · Sentinel)
Community content is available under CC-BY-SA unless otherwise noted.