A gravity gun is a type of device in video games, particularly first-person shooters using physics engines, whereby players can directly manipulate objects in the world, often allowing them to be used as projectiles against hostile characters.
The concept was popularized by the gravity gun found in Valve's Half-Life 2, as well as the Temporal Uplink found in Free Radical Design's TimeSplitters: Future Perfect; although a similar concept was used by id Software during the production of the earlier game Doom 3, eventually leading to the introduction of a physics-based weapon in the expansion pack Resurrection of Evil.
The secondary trigger attracts the targeted object to the gun and holds it in midair a few inches away, negating its weight and allowing the player to carry it with them.
The gravity gun, however, cannot manipulate heavier objects and enemy characters until the late stages of the game, when the device becomes temporarily infused with dark energy meant to destroy it.
He did, however, discuss its historical precedents, further stating that "The ancients learned very early how to use gravity to their advantage — but this usually involved rolling rocks down hills or pouring boiling oil down the castle walls.
In Future Perfect, the Temporal Uplink played a much larger role than that of its previous, map and mini-game oriented functionality, which the device was originally used for in TimeSplitters 2.
Worn on the wrist of the main player character Sergeant Cortez, the uplink provides a map and the ability to pick up and throw objects, as well as the capability to activate switches remotely.
This makes it an especially useful weapon for dispatching larger groups of enemies in the event that the player comes across one of the many explosive barrels placed throughout maps in the campaign mode of the game.
The device is noted in the Doom 3 storyline as an "ionized plasma levitator", created by the Union Aerospace Corporation for moving hazardous materials and a forerunner to tractor beams.
One key ability of the grabber is its capacity to lock on to the fireball projectiles cast by some hostile non-player characters, allowing players to turn the attack against their foe.