GURPS Pulse Guns
This is just an excuse to use GURPS Tactical Shooting with ray guns in a modern setting. Basically back in the early 70's a hobbyist found an obscure physical law that allows easy creation of ray guns from common materials. After some attempts to restrict them, the governments are now resigned to proliferation and its blasters for all. Other uses for this tech however have not seemed to come about so, its whatever the technology of the era is plus blasters.
These weapons are heavily armor piercing (armor is 1/5 as effective) and a bit more deadly and nearly recoiless but are semi auto only (6 shots per second is too much for sustained fire) and limited to a very heavy machine gun in damage (which will penetrate the side armor of a tank or the front of an APC)
Characters would be urged to take luck as hits are easy and deadly and cover only helps a little otherwise its blog standard GURPS.
The Return of Planescape? - Curious. There is a brief note on this 'countdown' at Enworld.
13 hours ago