fallout-4
I've read that high-defence settlements (where the defence rating is higher than the combined food & water value) will not be attacked. Elsewhere, I have read that even high defence settlements can occasionally be attacked. Which is true? What is the maths/algorithm behind the chance of a settlement being attacked?
I think it would be a shame to create a very high defence settlement, armed to the teeth, if it were never going to be attacked so that you could witness those defences in action.
Yes - I've had multiple instances where my turrets have opened fire on Deathclaws and other wasteland wildlife, the moment one of your defences start attacking (whether that be a settler shooting something or a turret opening fire). The attacks will kill settlers and destroy (reduce durability to zero) defensive structures and crops. You'll get the opportunity to fix any damaged structures or crops but if settlers die, that's final.
This means you'll want to ensure the approaches your settlements are well guarded and that you should position your defences for optimal coverage. However, I have noticed that in some instances when you don't turn up to a help a settlement that is under attack an unexplainable amount of damage will occur to your defences anyway... they do seem to help anyway and it might just be a coverage thing, and they're certainly helpful if you do respond to the settlement's call for help.
One of the earlier tooltips in the game indicate that your chance to get attacked is based on a your resource generation in comparison to your defence rating, and that you should keep your defence rating equal or better than your combined resource generation.
They'll destroy as many structures within the settlement and kill as many people as possible. You'll have the opportunity to repair anything that is broken in Workshop mode:
Obviously if settlers die, that's final.
For a duration of time, the happiness level of the settlement will also be impacted. This is especially the case if sufficient damage has been caused to the structures of the settlement to cause a shortage in any resources (power, water, food).
Best Answer
Yes, they can be attacked.
There's a reddit thread where this is discussed, including a formula. The thread is 4 months old, so it's possible this has been tweaked in a patch since then.
I've copied over the formula for raid chance and associated notes, with some formatting improvements:
So the chance of attack is always at least 2% per day (unless it's already been attacked in the last week or there are no settlers), but it's not hard to get it that low.