Better Settlement Attacks

Zombies are attacking Sanctuary!

Refactoring is an ongoing effort with Zombie Walkers and this time I have revisited settlement attacks once again. Settlements are a cool addition to Fallout 4 and lend themselves to the zombie apocalypse play-through as survival havens. As such, I want to make defending them actually matter.

What was wrong?

The first implementation used the game's built-in settlement attack quests. These are unfortunately a bit buggy due to the nature of all the code involved. Also, I feel a bit out of control in that I fire it off and sort of hope it works. I've had more than one user report being notified that an attack was happening and then not seeing any zombies. Others have reported setting settlement attacks to 100% and then never having their settlement attacked. Neither of these are acceptable.

A new approach

The settlement attack quests have a lot of logic involved in determining whether an attack should occur and where. In my mod, I just want to add extra attacks against the settlement you are currently at and the how often is a simple percentage checked hourly. Zombies now attack even if you have 0 food, water, and settlers.

To execute the attack, I use a quest alias to get a settlements LocationEdgeMarkers just like the game's built-in settlement attack quests. For the zombie attacks, I randomly choose one side to attack from only as zombies aren't smart enough to coordinate multiple attack vectors. The number of zombies that spawn is now controllable via a holotape option (from 10 to 30). Note that I've chosen to always spawn a minimum of 10 and the default max is 20.

Once spawned, the zombies are given a reference alias to the settlement's workshop (also bound via quest alias) so they path toward it. This workshop alias is a much simpler way to get a reference to the currently location's workshop than what I was doing which I'm not going to go into here.

I have chosen to retain the "Zombies are attacking ..." message to notify you of the attack but no longer have a message indicating the attack is over. This is due to not keeping track of the attacking zombies which the game built-in quest was doing. I didn't think it was necessary anyway. 

Another side effect of this new approach is what happens if you run away from the attack. In the games built-in quest your settlement structures can become damaged and possibly settlers killed. In this new approach, the zombies will eventually congregate around the workshop if you have no settlers. Having settlers may result in a long battle that the settlers will eventually win unless you have 'Kill Protected' enabled.

More than just zombies

The old implementation actually disabled settlement attacks from anything other than zombies since I was tying into the game's built-in quests and it was the only way to be sure a zombie attack happened when I wanted it to.

Now that I am executing the attack myself, I was able to restore the game's built-in settlement attack functionality so you can be attacked by raiders/super mutants/etc. again. I guess in theory you could be attacked by raiders and zombies at the same time, though it would probably be pretty rare.

A couple things to note though:

1. the settlement attack holotape options only affects zombie attacks (frequency/max size)
2. the replacement holotape options may still replace certain settlement attackers

Sanctuary Hills bug

One of the spawn points in Sanctuary was not working properly. It is the one near the main bridge that is actually located up in a tree off the ground (don't ask me why). Whenever this spawn point was chosen either zombies didn't spawn at all or they spawned in the nearby house near the bridge (the one not completely destroyed). To fix this, I moved the spawn point (via script) to the other end of the main Sanctuary bridge where I thought it belonged anyway.

Sanctuary Hills LocationEdgeMarker up in a tree that was moved to the other end of the bridge.

Future ideas

I'm already thinking about possible future enhancements. One thought revolves around putting a real negative consequence to abandoning your settlement during an attack. Maybe all your settlers die, the zombies stick around, and you lose control of the settlement until you clear the zombies and re-activate the workshop?