Me and my buddy, InnerNoob, found this glitch that allows four players to be infected without any humans on the survivors side, sadly, it does not work the other way around. This glitch is only for fun, since you can't actually progress through the campaign. This only works on the first chapter of the campaigns, because the survivors only remove the bar from the safe room door and then try to unlock the back door.
it also doesn't work in L4D2
innernoob1 2 years ago
we triedit on crash course it works and the AIs do use the artillery gun blockade thing
innernoob1 2 years ago