How do settlement attacks work?

[Fatum]

So far I've been able to ascertain that each has set spawns. I know they will move depending on how long it takes to fast travel in to my settlement. But is there a way to cause more attacks? I want to test my defenses as well as just check it out in general.

[Yhwach]

There's enemy spawn markers outside of the settlement's build area, some have it so enemies spawn "inside" which has never been addressed, but mods fix this.
To cause more attacks, simply have your defense lower than your resource count.

[Fatum]

Heh.. that should be easy. I have a mod that adds many new items. So my settlement has nuclear reactors and more power than I'll probavly ever need. Just need to keep them safe.

[DEVOLVE MINHA CACHAÇA!]

Like @Light says, there are fixed spawn points that determine where attackers will spawn if and attack is triggered. These are not always used by the engine, though, you might end up with attackers spawning in the middle of the settlement depending on how you decide to travel back to help defending against an attack and how much time it takes.

Regardless of how happy or defended is your settlement, the minimum chance of attack in a settlement is 2% per day. The chance increases the more resources (water, food) you have and decreases the more defenses you have.

Also, having trapped creatures (with Wasteland Workshop cages) not only heavily increases the chance of an attack but can also force the attack group to be of the same species of the creatures you have trapped.

Also, there is a mechanic in the engine take randomly decides if you win or lose an attack when you are away from the settlement being attacked. If the engine decides you won the attack, everything will be normal, but if you lose, random items you previously built there will be chosen by the engine to be damaged during the attack and you'll have to repair them as soon as you get back. That includes power generators, water purifiers, scrapping stations and turrets.

[Fatum]

I plan to build my island settlement up huge and leave the rest as just hubs to supply my main "fort"
So I'm anxious to see how attacks will unfold before I build up too much more.

[DEVOLVE MINHA CACHAÇA!]

Originally posted by Fatum:

I plan to build my island settlement up huge and leave the rest as just hubs to supply my main "fort"
So I'm anxious to see how attacks will unfold before I build up too much more.

If you do not care for aesthetics or lore, do it practical: do not surround your settlement with wallsm (because walls are essentially useless for defense purposes), and point your defenses directly to the spawn points, and put some some defenses close to the middle, so you can dispatch any random attacker spawning inside.

[Yhwach]

Win chance is determined by what type of enemy is attacking the settlement, they each have their own reflective values and a formula.
Such as raiders having the 2nd lowest rate next to a feral ghoul attack.

There's no 0% chance of a settlement attack, here's how it works:

Lowering modifiers

Each value in defense lowers the attack chance by 1% to a minimum of 2% attack channce
Each settler you have lowers this by an additional 0.5% to a minimum of 2% attack chance

Increasing modifiers

Every crafting bench and store increases
Each unit of food and water further increases the chance of an attack by an additional 0.2%

Final Modifier

Each "food", or "consumable" item such as purified water increases the chance of an attack by an additional 0.1%

The final formula goes a little like this, according to behind the scenes values by certain tools and the creation kit:
Increasing Modifier - Lowering Modifier (to a minimum of 2%) + the amount of consumables you have in the workshop, so there's a fair chance of an attack.
That means if you have a lot of purified water in your workshop, such as 200 of them, there's a fixed 22% chance regardless of defenses.

[Fatum]

Well I will wall it off, but only for my own flavor. I was aware of the spawning inside part from early on. But I will have a large guard tower with turrets and, if I can figure out how to force a specific settler to stay up in the tower (assign them to a guard tower building part) with a strong sniper.

Only question I have to figure out for myself is will i need one or two. Depends how large i make my town and the range on my turrets.

[RangerX3X]

Can you wire your turrets to a switch and turn them off to temporarily lower your defense rating to trigger an attack, then turn the power back on during the attack? That seems like it would be fun.

[Yhwach]

Originally posted by RangerX3X:

Can you wire your turrets to a switch and turn them off to temporarily lower your defense rating to trigger an attack, then turn the power back on during the attack? That seems like it would be fun.

As long as the defense lowers then it highers the chance, it may not update right away or if you're in the settlement so try fast travelling away after you do that due to lost values in the pipboy.
That doesn't always mean that your settlement is missing anything, It's just that the pip-boy can't retain values for all the settlements very well, but it can effect attacks too.

[Fatum]

Oh, another important question. What do attackers focus on? Do they try to fight their way to a specific thing? My guess would be the workshop bench if that's how it works.

Or do they just attack any thing near their spawn?

[DEVOLVE MINHA CACHAÇA!]

Originally posted by Fatum:

Oh, another important question. What do attackers focus on? Do they try to fight their way to a specific thing? My guess would be the workshop bench if that's how it works.

Or do they just attack any thing near their spawn?

Attackers will simply target settlers and turrets (and the player, if you are around, of course), and also try to steal equipment you have stored in containers and are within reach, as well as any power armor lying around.

[Fatum]

Originally posted by Mr. Dawn with Keys Hat:

Originally posted by Fatum:

Oh, another important question. What do attackers focus on? Do they try to fight their way to a specific thing? My guess would be the workshop bench if that's how it works.

Or do they just attack any thing near their spawn?

Attackers will simply target settlers and turrets, and also try to steal equipment you have stored in containers and are within reach.

Ok, so good loot will go in my towers. Lol

[DEVOLVE MINHA CACHAÇA!]

Originally posted by Fatum:

Originally posted by Mr. Dawn with Keys Hat:

Attackers will simply target settlers and turrets, and also try to steal equipment you have stored in containers and are within reach.

Ok, so good loot will go in my towers. Lol

Exactly. If you store precious loot, such as legendaries, in containers, put them in places that NPCs can not easily reach, so you can prevent both settlers and attackers from stealing your stuff. Yes, settlers can als sniff around your containers to get better equipment if they are attacked and their current gear is weak enough.

[Borrolan]

Slightly tangential point.

In the past, I've mumped and moaned about settlement defences being useless...if the player doesn't turn up to help out. Turns out I was talking utter kerrap.

During this play through I've had 2-3 messages pop up, informing me that settlement whatever had successfully defended itself. All my settlements have missile turrets, which may have been a factor. Settlers also have high grade weapons, although I'm not sure how the game scripts could factor that in as a calculation, during a battle where the player is not present. When the player IS present, high end weapons used by settlers do seem to have an effect. That's not based upon anything substantive; it's just an impression.

Anyway, just admitting I was completely wrong.

The frequency of the attacks seems much lower than in previous play throughs. Picking up on Light's point, I now keep my resources at a minimum in settlements that are populated (and thus subject to potential attacks) Whether the attacks are now less frequent I can't say for sure. That's my impression though.

As for spawn points, I think it was casual sailor who said something about spawn points and time taken to attend the scene. I always respond whenever I notice the message. Enemies now seem to appear at the perimiter of any, given settlement. In this play through I've yet to see enemies spawn in the core, settlement areas. In other games, I've seen them spawn next to a fast travel point if I was slow to respond.

[Vyvyvn]

I usually just have the NSA mod installed so settlement attacks never happen, But they can still be attacked by wandering npcs and kidnapping and other such quests still happen. I just got tired of having to often literally drop everything to run back just in the odd chance the engine threw a bad dice roll or two while I was away. :P

EDIT: That, And having to plan my settlements around possible attacks rather than what worked best for npc naviagation and aesthetic bothered me.