HaloMods "Classic" Read-only Archive

Sometimes when im on Halo I join a server and there are turrets places around the map. How can I make a mod for this? And why do they show when I join? When I make most mods the players cant see any of the changes, they just get owned from random things.

Cheers

the only thing you can change on netgame mods are player spawns,equiptment,vehicles and netgame flags