I would like to see a script that would simulate CS. I was thinking of something that works like combining the visual effects of a smoke grenade with the stun effect of a flashbang. The flashbang effect part would take a second longer to take effect and would last several seconds in duration (15-30 seconds). The last part of this would be the gas victim would fall into the prone positon for the duration of the effect. I think that part would be relatively easy but still beyond my scripting ability.
The hard part would be how to simulate a new person walking into the gas cloud, especially inside a building. In theory, a new victim would be affected but not as badly. The new victim would be affected as if trying to see at night (watering eyes) and their aim would be poor (as if hand struck). You could add a gasmask script so anyone wearing one wouldn't be affected at all. Now we are getting more complicated.