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Zero Point Energy Field Manipulator

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This subject is related to the Combine era.

This article is about the Half-Life 2 weapon. For the cut Half-Life weapon, see Zero Point Generator. For the fan film, see The Gravity Gun (fan film).

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Gravity Gun.jpg
Gravity Gun super.jpg
Zero Point Energy Field Manipulator
Production information


Technical specifications
  • Varies depending on the object/Normal
  • Instant Kill/Super


Max ammo


Weapon category


Ammo type





Short to medium


Eli Vance

Used by
Game information


"The Zero Point Energy Field Manipulator is not a toy, Alyx!"
Judith Mossman[src]

The Zero Point Energy Field Manipulator, more commonly known as the Gravity Gun, is a handheld gravity-based device first appearing in Half-Life 2. Said to have originally been designed for handling hazardous materials, Alyx Vance mentions that it was used primarily for heavy lifting at Black Mesa East. After acquiring it, Gordon keeps the device in his arsenal and uses it all the way to the end of Half-Life 2: Episode Two. At its core is some sort of gold-colored substance which is implied to be a Xen crystal by The Final Hours of Half-Life: Alyx. Introduced to Gordon by Alyx shortly after his arrival at Black Mesa East during Half-Life 2's fifth chapter Black Mesa East, the Gravity Gun soon becomes an invaluable tool in Gordon's arsenal and is now considered one of his signature weapons.


Alyx introducing the Gravity Gun to Gordon at Black Mesa East.
  • The Gravity Gun has two basic modes. The primary fire releases an energy blast, which pushes the targeted object with a tremendous force. This is useful in-game for clearing out barriers, or moving objects that cannot be picked up, such as disabled cars. The secondary fire pulls objects towards the gun, and holds them just ahead of the device. These objects can then either be dropped by pressing the secondary fire button a second time, or they can be launched forward with the primary fire. The secondary fire can only pick up lighter objects — mainly those which Gordon himself can carry, with some exceptions — but the primary fire is capable of pushing much larger objects even if the secondary fire cannot affect them. The gun's secondary fire cannot lift living creatures and also does not lift most corpses, though the primary fire can shove Antlions and Headcrabs away.
  • Using the Gravity Gun's secondary and primary fire modes in conjunction allow it to be used as a powerful weapon. Since it uses physics objects rather than conventional ammunition, there is virtually no limit to how many times it can be fired. However, this advantage is balanced by the need to "reload" after every shot, by grabbing a new object. Depending on the object fired, the Gravity Gun can be one of the most damaging weapons in the game. Heavier objects like metal barrels and propane tanks can even kill an Overwatch soldier with a single blast, but conversely, objects such as plastic crates, plastic bottles, or wooden pallets will do very little to no damage due to their weaker materials. Explosive barrels, in particular, are highly devastating when used with the Gravity Gun, but this can backfire if the barrel is shot by an enemy while being held by the gun. The Gravity Gun is most effectively used as a short to mid-range weapon, since the physics objects it uses for ammunition are affected by gravity once they leave the device's hold.
  • The secondary fire of the Gravity Gun grows weaker with distance. Outside of a certain range, it is able to pull objects closer, but much more slowly and the object is still subject to Earth's gravity. The gun must also be constantly trained on the object to maintain the pull until it has been captured.
  • In addition to its primary uses, the Gravity Gun can be used in more esoteric ways. Manhacks, City Scanners and Shield Scanners can all be held and punted by the gun; the first, in particular, can be held by the gun for use as a makeshift chainsaw. All three are heavy enough to deal significant damage if pushed, and will be destroyed if pushed into a nearby wall. However, if pushed over greater distances, they will stabilize their flight. It can also be used to grab and recalibrate Hopper Mines or remove Rollermines from vehicles. A Rollermine grabbed in such a manner can be reprogrammed by Alyx to attack hostile targets instead of friendlies, and can also be pushed into enemies directly. Combine Sentry Guns can also be manipulated by the gun (disabled by being thrown when being enemies, replaced after being knocked down when being friendly).
  • In addition to its use as a weapon, the secondary fire of the gun can be used to pull objects over from a distance, allowing Gordon to access supplies or other objects, that are out of reach or behind a Force Field.
  • The Gravity Gun is also handy for moving trapped vehicles, such as the Scout Car, as well as the Muscle Car. This is particularly efficient for flipping the Scout Car, if it flips over onto its roof.
  • Though the gun cannot affect most organic matter, Headcrabs and Antlions are vulnerable to the primary fire. Three blasts from the primary fire will kill any Headcrab. Antlions take considerably longer to kill in this manner, but being hit by the gun causes them to flip over for a few seconds, allowing for a safe kill or getaway.
  • It can also be used as an alternative to the crowbar for smashing supply crates open by picking them up and pushing them into the wall. Even simply punting a supply crate will break it, which is faster than using the crowbar. This becomes mandatory during the first half of Episode One, during which Gordon is without his crowbar, until Barney Calhoun gives him a new one in the game's fourth chapter, Urban Flight.
  • Another useful strategy is throwing back a Fragmentation Grenade to its sender. This can be dangerous, however, as the grenade can detonate while the player is holding it.
  • Heavy objects, such as disabled cars, or even some pieces of furniture can only be pushed using the primary fire. Cars can kill several enemies at once and are also useful in Episode One, when Freeman must block several Antlion holes with them.
  • The Gravity Gun can also be used to grab larger objects, such as metallic plates or radiators, and holding them up as makeshift shields. This was demonstrated by Valve in the E3 2003 demonstration Traptown.
Dog's Zero Point Energy device.
  • The tutorial for using the Gravity Gun takes place in Black Mesa East's outdoor scrapyard, in which Alyx teaches Gordon the basic actions and uses of the device, notably by playing fetch with Dog and his own reprogrammed Rollermine, until they are interrupted by a Combine attack, forcing Gordon and Alyx to separate.
  • Ravenholm was built around the use of the Gravity Gun, as it contains most physics elements seen during the series. Indeed, one of its early names is "Phystown". One of the achievements in Half-Life 2 is beating the Ravenholm chapter using only the Gravity Gun to dispose of enemies.
  • The Gravity Gun is quite heavy, as Alyx Vance and other characters that attempt to use the gun have some trouble lifting it. It also has significant recoil, as demonstrated when Alyx uses it to push a train door away. However, Gordon Freeman's HEV Suit presumably allows him to use the device with ease.
  • Judith Mossman takes the Gravity Gun very seriously, and advises Alyx to do the same in her infamous sentence "The Zero Point Energy Field Manipulator is not a toy, Alyx!".

Common objects[edit]

Most common objects found in the environment that can be picked up by the Gravity Gun and thrown at enemies, among others. Non-exhaustive list.


Includes "random" items found in the environment. Some items are very light and thus useless for gameplay. Some are heavier and can be used against opponents.


Environmental explosives that can also be detonated with bullets, and may backfire when shot at by enemies.

Useful items[edit]

Also includes every single weapon and ammunition. All health/armor pickups are based on the 100 point limit.

Organic Variant[edit]

  • When exposed to the Confiscation Field in the Citadel, the Gravity Gun is "supercharged", rather than being vaporized as Gordon's other weapons are. It also cripples the field itself in the process. Once supercharged, the Gravity Gun emits blue light rather than orange, quakes in Gordon's hands, and creates small bolts of energy across its muzzle. Its powers are vastly enhanced, enabling it to manipulate objects of far greater mass than it could normally (such as Combine interfaces), as well as pull and repel them with greater force.
  • Its most significant enhancement, however, is its ability to manipulate living, organic matter. Any Overwatch unit pushed by its primary fire is instantly killed, and their body retains an energetic charge, that will kill others if it strikes them. If grabbed by the gun's secondary fire, they are likewise killed instantly.
  • It also appears to have the side effect of vaporizing any weapon the soldiers are carrying, even when they are killed indirectly by a thrown object. However, this also occurs when Alyx kills an enemy herself using her handgun, as well as when the soldiers are killed by their own grenades or other causes, suggesting a Citadel-wide security measure destroying their weapons rather than a Gravity Gun induced effect.
  • Like the normal Gravity Gun, it can also pick up Energy Balls and send them flying towards enemies, similar to the Pulse Rifle's secondary firing mode.
  • The first time the Gravity Gun is supercharged is in Half-Life 2’s thirteenth chapter, Our Benefactors, when Gordon's Prisoner Pod deposits him into a Confiscation Field; it remains supercharged until the end of the game.
  • At the start of Episode One, it is no longer supercharged, but becomes supercharged again after Gordon and Alyx re-enter the Citadel to stabilize the core, when Gordon accidentally enters another Confiscation Field. It remains supercharged until Gordon reactivates the core's containment field, at which point the Gravity Gun reverts to its normal state.
  • In Half-Life 2, the supercharged Gravity Gun's primary fire has the same fire rate as the normal version. This is not the case in Episode One, where it can be fired as fast as the trigger is pulled.

Related Achievements[edit]

Any Half-Life 2 game
Hlx kill enemies withphysics.png Bone Breaker (5G)
Kill 30 enemies with thrown physics objects.
Hlx kill enemy withhoppermine.png Deadly Harvest (5G)
Kill an enemy by planting a Hopper Mine.
Hlx kill enemies withmanhack.png Hack Attack! (5G)
Kill five enemies with a Manhack.
Hlx kill soldier withhisgrenade.png Hot Potat0wned (10G)
Kill a Combine soldier with his own grenade.
Hlx kill enemies withoneenergyball.png Conservationist (5G)
Kill five enemies with the same Energy Ball.
Hlx kill elitesoldier withhisenergyball.png Think Fast! (10G)
Kill an Elite Soldier with his own Energy Ball.
Half-Life 2
Hl2 get gravitygun.png Zero-Point Energy (5G)
Get the Gravity Gun in Black Mesa East.
Hl2 makeabasket.png Two Points (2G)
Use Dog's ball to make a basket in the scrapyard.
Hl2 beat ravenholm noweapons.png Zombie Chopper (25G)
Play through Ravenholm using only the Gravity Gun.
Hl2 kill enemy withtoilet.png Flushed (5G)
Kill an enemy with a toilet.
Hl2 disintegrate soldiersinfield.png Atomizer (10G)
Disintegrate 15 soldiers by throwing them into a Combine ball field.
Half-Life 2: Episode One
Grave Robber.jpg Grave Robber (5G)
Steal a Zombine's grenade.
Zombie-que.jpg Zombie-que (5G)
Use flares to light 15 Zombies on fire.
Car Crusher.jpg Car Crusher (5G)
Use the cars to squash 15 Antlions in Episode One.
The One Free Bullet.jpg The One Free Bullet (40G)
Finish the game firing exactly one bullet. Grenade, crowbar, rocket, and Gravity Gun kills are okay!
Half-Life 2: Episode Two
Grave Robber.jpg Grave Robber (5G)
Steal a Zombine's grenade.
Ep2 kill chopper nomisses.png Puttin' On a Clinic (15G)
Defeat the chopper in Episode Two without any misses.
Ep2 kill hunter withflechettes.png Payback (10G)
Kill a Hunter with its own flechettes.

Behind the scenes[edit]

  • In an interview with RetroGamer magazine, David Speyrer stated that Jay Stelly had built an in-game tool, originally dubbed the "Physgun", that allowed the developers to pick up props and reel them in or push them away with an energy beam. This device would eventually evolve into the Gravity Gun.[1]
  • During Half-Life 2’s development, the Gravity Gun had several names, including: "Zero-Point Gun"[2] or "prototype physics manipulator".[3]
  • As heard in sound files featured in the Half-Life 2 leak files, Eli was to explain to Gordon at Black Mesa East, that while Black Mesa was a "decade away from harnessing the zero-point energy field", it turned out that the Combine had already pioneered this technology. He then explains that the Gravity Gun is based off "a little piece of tech Alyx liberated on one of her expeditions". He also calls the Gravity Gun's secondary fire mode "asymmetric". The Gravity Gun's "grand daddy" was used to manipulate hazardous materials in the Combine's portal reactors, suggesting the Gravity Gun uses Combine technology.[2]
  • At some point during Half-Life 2’s development, Ravenholm was set at the end of the Canals, and preceded Black Mesa East. Consequently, it didn't include the Gravity Gun, and as such, its gameplay only focused on Father Grigori's intricate traps (hence the name being used at that time, "Traptown").[4]
  • The Gravity Gun bears a vague resemblance to the Anti-Mass Spectrometer from Half-Life, notably the prongs. The Aperture Science Handheld Portal Device from the Portal series has some similarities as well; it was actually originally based on the design of the Gravity Gun, as seen in early Portal screenshots. It retained the prongs in the final design, as well as a zero-point energy field manipulator (also used by Fetchbot[5]), allowing it to pick up small objects, but not launch them like the Gravity Gun.[6] The Gravity Gun can also be seen in the Enrichment Center lab where Doug Rattmann and Henry are working prior to GLaDOS killing its inhabitants, in the comic Portal 2: Lab Rat. Interestingly, in that same comic panel, we can also see two Black Mesa health and energy chargers, as well as what seems to be a Combine health charger. Marc Laidlaw confirmed that these were placed as a tribute to Half-Life, and nothing more.[7]


  • When the player dies using the supercharged Gravity Gun, it disintegrates.
  • Despite being arguably Half-Life 2's main weapon, outside of the game's ending sequence in the Citadel, the only times it is actually required to be used is to disable the three generators in the Overwatch Nexus. The Gravity Gun tutorials in Black Mesa East's scrapyard can be skipped by just waiting during the the punting tutorial, climbing up using other props in the area to knock over the barrels that Alyx wants you to grab with the Gravity Gun in the grabbing tutorial, and either waiting or stacking up props without the Gravity Gun to reach Alyx in the stacking tutorial.
  • The film District 9 features an alien weapon influenced by the Gravity Gun, built into a powered armor suit. It is able to pick up almost anything, including a pig, and hurl it with incredible force. It appears to have a much stronger field since it is also able to halt bullets and in fact keep them in an area just ahead of the muzzle, somewhat similar to a zero-point energy field.



HUD icons[edit]



List of appearances[edit]

Zero Point Energy Field Manipulator
Combine OverWiki has more images related to Zero Point Energy Field Manipulator.

Main games[edit]