Raid AI

[Dertrend]

It seems the raiders are primarily focused on killing the settlers which in my opinion makes defence a bit too straight forward. It might make the game more challenging if the raiders caused general destruction to buildings and actually tried to pick up items of value.

[Naia000]

And yet, there are plenty of forum posts complaining about raiders showing up whit trebuchets and destroying half the base...

Now, I don't disagree that it can be easy to defeat attacks. Surrounding your base with high walls. Equipping everyone with ranged weapons and placed on top of those walls, and plenty of traps below, you can defeat quite a lot of enemies. If that is what you want.

But you can also build a more open base, that is difficult to defend and chose to equip everyone with melee weapons. Then things become more challenging.

At least that's what I'm attempting. How well it works out remain yet to be seen.

[MEGADORI]

What I've seen so far is that raiders will attack settlers they can route to, and if there is none they can reach, then they will attack production buildings, and if they can't route to one of those either, then they will attack doors and try to get inside.
By accident, I discovered how to exploit that and make defence very easy.
Build a funeral pyre outside the walls and near a gate, and inside the walls build a simple watchtower for rangers. Any attackers will run straight for the funeral pyre because it is a production building and they are hellbent on destroying it. As they approach you can start shooting from the tower, and it also helps to put traps around the pyre and in front of the door. After destroying the pyre, the raiders will try to break through the door. You can still shoot at them, and if any manage to break through, have your melee fighters ready behind the doors.
What I think makes the attacks very cheesable is not the AI however, but the lack of means for attackers to climb walls and cliffs and get over gaps.
The best defence strategy at the moment is to force attackers to use a certain route where you can pick them off with rangers. By building walls with a deliberate gap, or in a mountainous terrain simply by destroing any natural ramps that allow access to the level where your settlement is except for the one you want everyone to take, then you don't even need a wall. A raised road as a way in needs just a one tile gap (which is covered by simple wicker floor while no attacks are happening) to be unroutable for raiders. If they had ladders to get over walls, up and down cliffs, and over narrow gaps, that would change the whole game.