Splash damage is a skill that can be used to damage multiple people with one shot or to propel them through the air. It's a common strategy to fire at an enemy's feet with the Rocket Launcher, as a direct hit is not necessary with the large radius of splash damage. Damage dealt will lessen the further away the target is from the point of impact but can toss them with greater force enough to make them airborne and disrupt them for a second.
Splash damage is most often dealt by explosive weapons in the series such as Grenade Launchers and Rocket Launchers. To a lesser extent, the Plasma Gun from Quake 3 Arena and Nailgun from Quake Champions are also capable of dealing a small puff of splash on impact. BFG 10k in Quake 3 Arena is also unique for dealing splash damage, while BFG 10k in Quake 2 and Dark Matter Gun in Quake 4 can not. In Quake 4, the setting for splash damage is slightly altered in id Tech 4 engine, direct hits will not deal extra splash damage, this applies to Grenade Launcher and Rocket Launcher. Splash Damage can also be caused by an explosion from a Radioactive Container.