HL2 article
This article is about the Combine ball. For the Aperture Science energy ball, see Aperture Science High Energy Pellet.

The Combine Energy Ball,[1] also known as Energy Orb,[1] is a concentrated sphere of Dark Energy plasma, a form of exotic matter that disrupts space-time and distorts light.


Energy Balls are generated by Combine Dark Energy reactor systems and transmitted through the plasma conduits of Citadel power transfer systems. Energy Balls can be contained within specialized dark energy cores, portable long-term storage devices that can later be used in Combine dark energy devices. As well as power generators, dark energy cores can be used by the Pulse Rifle, which can store the energy until released by the rifle's secondary fire. Despite the weapon common availability, only Overwatch Elite are allowed to fire the Energy Ball.

Energy Balls repel themselves from matter of sufficient mass and density, bouncing off walls, ceilings and floors without losing momentum. However, when they strike matter of low density or mass, they are absorbed, causing them to dissolve into nothing. Gordon's HEV Suit, being plated, may explain why the player will sometimes deflect the orb rather than absorb it upon impact.

Energy Balls are subject to zero-point energy fields, allowing them to be grabbed and manipulated by the Gravity Gun. OSIPR-fired Energy Balls can be caught by the Gravity Gun and fired back at their source, though if held for too long, it may explode. Doing this will earn the "Think Fast!" achievement.

Strangely, the Energy Ball seems to be somewhat attracted towards organic matter. When bounced off a solid object, the Energy Ball is likely to slightly change direction towards the nearest enemy despite the fact that its vector should point elsewhere.

The Energy Ball is used towards the end of Half-Life 2 to disable Combine Force Fields and ground turrets in the Overwatch Nexus. The player is required to use the Gravity Gun to force the orbs from Combine Power Generators and thus disable the connected components.


  • In Garry's Mod, the Pulse Rifle secondary ammunition orb is humorously named "Combine's Balls".
  • In Portal, the "Aperture Science High Energy Pellet" bears a remarkable resemblance to the Energy Ball. In fact, they use the same entity, except that in Portal it will always kill the player. Using impulse 101, it is possible to pick it up with the Gravity Gun and throw it, and it'll behave like a normal Combine energy ball. However, after using an AR2, or a gravity gun to throw it in, the catcher will not accept it.

Related achievements

Any Half-Life 2 game

Hlx kill enemies withoneenergyball Conservationist (5G)
Kill five enemies with the same Energy Ball.
Hlx kill elitesoldier withhisenergyball Think Fast! (10G)
Kill an Elite Soldier with his own Energy Ball.


List of appearances


  1. 1.0 1.1 Half-Life 2 Prima Guide
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