Increases defense multiplier of base by one. This effectively doubles defense
strength ( or triples it when combined with a Tachyon
Field )
The Perimeter Defense is your most basic defensive facility,
and as such it is pretty much a necessity for any new base. It's so essential
that there's no reason not to grab the Citizen's
Defense Force secret project if you can, and make a Perimeter Defense part
of your infrastructure.
If you don't get the secret project, then do some prioritizing when building your perimeter defenses. Bases near another faction's boundary, or on an exposed stretch of coastline, should get perimeter defenses right away, but then these bases can act as a line of defense for your interior bases, which don't need defenses until later on. Even with these priorites, however, it's still a good idea to eventually build defenses in all your bases, to protect against eventualities like drop troops, wild mind worms and the possibility of a major enemy offensive bursting through your defensive line.
