X Game System
Players use lens and headphones, and get out on the streets with fake guns shooting each other.
The lens and headphones make all the magic, you see things blowing up, you losing an arm or something with a bullet.
It uses a wireless system with direct triangulation controls.
Weapons could include grenades, geo located, you just trow a placebo one. System detects its, everyone hear the explosion. Your buddy dies, you cry.