The only way the light beam idea works for me is if there is POV flying and a way to determine distance between target and shooter for maximum effective range. There also needs to be a very limited amount of "ammo" to shoot.
Somebody will come up with an entertaining and fairly realistic way of doing this with actual models instead of just a video game....it's just a matter of time. How to package it into an economicaly feasible package is the key. I'd also like to see an invisible fence set up to keep the action confined to whatever sized combat box I desire. Stray outside the box and lose points by the second.