“	Like the Quad Damage, this item doubles the damage you inflict on your enemy with any weapon.	”
—Ground Zero Manual

Double Damage is a new power-up introduced in Ground Zero, appearing in both single-player and multiplayer. Once activated, the players' weapons will deal twice as much damage as they would normally. Essentially it's a weaker version of the Quad Damage - granting a significant advantage to its user, but not making them quite the unstoppable force that a Quad-powered player represents. But on the plus side, you can carry both in your inventory. Its effects lasts for 30 seconds.

In the original release of Ground Zero, Double Damage does not stack with Quad Damage; if you activated both at once, you'd benefit from Quad Damage but the Double Damage would have no effect. However, this is changed in the 2023 remaster; you can activate both at once and they will stack, multiplying your damage by eight.

With the 2023 remaster, Double Damage also appears in Call of the Machine.

The final boss of Ground Zero, the Black Widow Guardian, has the ability to use Double Damage too, but she will only use it on certain difficulty settings and only in response to the player using their own power-ups - see her own page for details.

Strategies

• The Double Damage is much more commonly found in the single-player Ground Zero campaign than the Quad Damage is (the campaign contains seven Double Damage, but only two Quad Damage) and so Double Damage should be a more frequently-used tool for tough fights such as when you're about to face a Medic Commander or the Carrier, whereas a Quad Damage should be saved for the Black Widow Guardian. The last Quad Damage is found halfway through Unit 2 in Waterfront Storage, so that's the one you'd need to keep in your inventory until the Black Widow Guardian. It is advisable to bring a Double Damage to the Black Widow Guardian fight as well, and the last Double Damage in the campaign is found in Unit 4, in the Ammo Depot.
• While you're under the effects of Double Damage, a Medic Commander would be killed by two Railgun shots instead of the usual four (note that this refers to the original game; in the 2023 remaster it would take three double-damage Railgun shots), and this is a very quick and reliable way of ending this potentially difficult fight before it becomes overwhelming. It's true that the BFG10k can potentially kill the Medic Commander in one shot, but it doesn't always work that way - for example, sometimes the Medic Commander might suddenly summon a Strogg into the path of the BFG shot, resulting in the Medic Commander surviving. The Railgun buffed by Double Damage is a more reliable method. If you are able to approach the Medic Commander unawares and fire the Railgun before it sees you, and if you have Double Damage active at the time, then it'll only take one Railgun shot to kill the beast (again, no longer the case in the 2023 remaster), due to the Railgun's ability to inflict double damage to an idle target. In the 2023 remaster, the Chain Gun buffed by Double Damage may be a better option than the Railgun.
• Whereas the other "combat boost" powerups (the Quad Damage, Invulnerability and Defender Sphere) each have a specific hotkey button to activate them (Q, I or F respectively), there is no specific hotkey button to instantly activate a Double Damage in the midst of battle. There are two ways it can be activated in battle - either you can bind a specific key to its activation (using the console, type "bind * use double damage", where * is your chosen hotkey), or you can instead cycle through your inventory to the Double Damage and then "use item". For this reason, it may be worth customising your "next item" and "use item" controls, and cycling to the Double Damage before getting into a tough fight, so that it could instantly be activated if needed. This is no longer an issue in the 2023 remaster thanks to the new inventory wheel.

Sounds

Sounds
Activation
Using
Expiring

Appearances

Ground Zero: Lower Mines, Tectonic Stabilizer, Eastern Warehouse, Tactical Command, Waste Disposal, Maintenance Hangars, Ammo Depot

Call of the Machine: Strogg Jammers, Echoes of the Past, Heavy Water, Surface Infiltration, Strogg Flesh Labs, The Mainframe, Turbine, Temple of the Creator

References

Quake II: Ground Zero
Organization		Terran Coalition of Man · Strogg
Characters		Stepchild · Wonimal · Zor · Scar-funkle
Enemies		Daedalus · Medic Commander · Stalker · Turret
Bosses		Carrier · Black Widow Guardian
Weapons		Chainfist · ETF Rifle · Plasma Beam · Proximity Launcher · Tesla Mine · Disruptor (2023 remaster)
Powerups		Antimatter Bomb · Defender Sphere · Doppelganger · Double Damage · Hunter Sphere · IR Goggles · Vengeance Sphere