The railgun has become a firm favourite weapon of players of the Quake series of first-person shooters, despite only having been part of it since Quake II. It is the series' nearest equivilant to a sniper rifle, and it is considered the mark of a true professional when one can pick off opponents with only a single, well-placed shot. It has so far appeared in Quake II and its mission packs, and Quake 3 Arena (with its expansion, Team Arena).
The weapon uses depleted uranium slugs as ammunition, firing them at colossal speeds until they hit concrete. In Quake II's single player, it was easily possible to fire through several weaker enemies with a single shot, gibbing all in its path; stronger enemies would typically take numerous shots to bring down. The weapon truly came into its own in deathmatch, however, where its unlimited range made it a truly dangerous weapon in the hands of a master. (The caveat, of course, was that it soon become known as a camper's weapon.)
Quake 3 Arena, being entirely multiplayer-orientated, toned down the weapon considerably: damage was lowered, and the already lengthy reload time was also increased. It still remains a powerful weapon, however, with one-shot kills being possible upon unarmoured opponents. Team Arena went even further, lowering the damage so much that the weapon's usefulness became quite questionable.
The Quake 3 version of the weapon also did away with the classic (some would say beautiful) corkscrew-particle effect that appeared when the weapon was fired in Quake 2. This was done to avoid horrendous drops in framerate when rendering the particles in the new engine. However, the effect can be reproduced by entering the following command at the console:
/cg_oldrail 1