Cost effective defense?

[Wanderer_joins]

Heironymous has the right idea, you don't need a lot of static defense in the early to mid game. Just build a lot of doors to your buildings and play peek-a-boo.

When the doors are opened and pawns shooting, can't the enemy simply walk inside?

The peek-a-boo or door dancing technique, is based on the time the AI loses retargetting. That's why you can use this technique exclusively early on (one caveat: manhunterpacks).

Later, massive raids will be more tedious to deal with in an open base, a perimeter wall will spread the raiders out.

[Hieronymous Alloy]

Heironymous has the right idea, you don't need a lot of static defense in the early to mid game. Just build a lot of doors to your buildings and play peek-a-boo. Make sure every room has a door to every adjacent room, so you can retreat and reposition internally. You really can't have enough doors.

Later on transition to Limdood's method when you have enough stone. I like to make my trap corridors like pic related, it really slows down centipedes as they bang on doors and bunch up. You can EMP and focus-fire them with little risk.

Thanks for all the suggestions guys. I'm curious about this layout. So when the enemy enters through the opening, my guys are positioned behind the doors? Like ~5 guys? When the doors are opened and pawns shooting, can't the enemy simply walk inside?

there are screenshots of a layout of this type in my guide. Just as one example:


http://i.imgur.com/zkWspNF.jpg

Basically you stand in the doorway and use the side walls that the doorway is in as your cover. When the enemy approaches you duck back behind the door. The door will generally close before the enemy has a chance to follow you, especially if it's an autodoor. It takes a fair bit of micromanagement but it's a very fun way to play the game.

You have to worry about friendly fire less than you'd think because each pawn has a slightly different line of fire and has cover behind them as well as in front.

To deal with the very large endgame raids you backstop the whole setup with a big killbox.