Zombies (Terrorists) have to use only the knife.(exception: on some maps, a machete is also allowed)
On zombie servers I discovered many times these problems:
some zombies just don't get this simple rule and shoot every CT down
a zombie accidently collects a weapon which just dropped on the floor, fires and kills some ppl. Bad luck for the zombie but also very annoying.So we have to find a way to make it impossible to zombies to even collect weapons. My solution simply don't let dying people drop weapons (because dropped weapons from dead people are the problem #1 on zombie maps, I think).
This is what you have to do:
Go to Options->More->Server - General. Set the values "mp_deathdrop" to "4" (Nothing) and "mp_dropgrenades" to "0" (Off). Don't forget to press "Apply" for each value change!2nd idea: If possible, don't choose a zombie map where you have to close doors to block access to guns. Maybe some players just forget it and an asshole zombie makes the berserker.

On the downside, CTs can't collect weapons from dead ppl anymore. But even worse are players who simply don't get the rules and this is the best soloution I've found so far. So what do you think?
Setting up a zombie server even noobs understand
1 
Setting up a zombie server even noobs understand
Offline
) = it lights the floor