A powerful weapon that is poorly named in not one, but two computer games.

In Syndicate, it is a kind of rocket launcher.

In Half-Life, it acts like a powerful maser. (Not a laser, since you can shoot it through walls).

This bugs me, because if it really was a 'Gauss' gun, then it would not launch rockets or shoot beams of coherent light, but would have to somehow set up a powerful linear magnetic field in front of the weapon. The result would be a kind of directed EMP that could fry circuitry and melt certain slightly resistive metals. However, this would take a whole lot of energy that would probably be better spent if you implimented it into a rail gun.