Fallout 4 Settlements

In Fallout 4, the Sole Survivor can build and manage their own settlements at various sites around the Commonwealth. The new workshop interface is used to place and connect pre-fabricated structures as well as individual pieces (walls, floors, roofs, etc.) letting the player character construct their own home base(s) as they desire.

Overview
Once built, these settlements can be customized extensively. Inside buildings and structures, furniture, decorations, and lights can be placed for aesthetic purposes; outside these structures, the player character can plant crops, create water and power supplies, and tend to the defensive needs of their new settlement. To accumulate resources for their settlements, the player character can scrap most interactive inventory items.

Once a settlement reaches a certain size and/or the player character obtains necessary perks, they can invite others to set up shop at their base by building unique resources such as the trading post, which adds a vendor NPC stocking some of the best in-game items. It is also possible to establish supply lines between settlements to share resources and inventory among them.

Settlements require constant maintenance with NPCs tending to more basic functions such as crop harvesting. However, without this, crops will fail and equipment will need repair over time. The player character will have to use the workshop and have the required junk to complete the repairs. Walking up to a damaged or failed item while in workshop mode, the player character will be offered a selection to scrap/repair the observed item.

Most of these sites can be obtained during the Minutemen quests; however, others will require visiting them and completing location-specific quests.

Settlement sites
 There are 37 discoverable/unlockable settlements total with 30 in the base game, one in the Automatron, four in the Far Harbor, one in the Vault-Tec Workshop and one in the Nuka-World add-ons. Most are obtained by completing an objective or killing hostiles/residents in the area then opening the workshop.

Quests
The Sole Survivor can acquire a variety of radiant quests from miscellaneous settlers. After joining the Minutemen, these quests are also obtained when talking to Preston Garvey or listening to Radio Freedom. These quests involve completing a variety of objectives for the settlers, from wiping out a nearby Raider gang to repairing a damaged generator. Completing these quests is the main way to acquire new settlements, and also provides a constant supply of busywork to earn caps and XP.

Recruitable settlers
Throughout the game, there are unique NPCs that aren't available as followers, yet can be persuaded to join an owned settlement, provided the requirements are met.

Related perks

 * Gun Nut allows for the creation of more advanced defenses.
 * Hacker is required for the creation of terminals.
 * Armorer is required to build power armor crafting stations.
 * Science! is required for the creation of assorted advanced power-focused structures.
 * Local Leader allows for two settlements to have a supply line, sharing resources.
 * Rank 2 of the perk is required for vendor stalls and crafting stations.
 * Cap Collector is an additional requirement for tier 3 shops.
 * Medic is an additional requirement for all medical shops.

Nuka-World
During the Nuka-World add-on, the Sole Survivor has the ability to lead the three raider groups included in the expansion (Operators, Disciples, and the Pack) and capture settlements through violence. These captured settlements are called raider outposts and will be populated by members of the raider group that helped capture it. While they will no longer be referred to as settlements by characters in the game, these outposts are settlements for the purposes of achievements and trophies.

The differences between a Minutemen settlement and a raider outpost are few but significant; for example, one can lead raiders to capture other settlements, extract tribute from Minutemen settlements, and make other settlements your vassal states. In addition, captured and intimidated settlements will pay the Sole Survivor in caps back at their home base in Nuka-World. After Power Play however, whatever raider group was betrayed, and any outpost they control will no longer pay tribute following the quest. This will start Cleaning House, where the Sole Survivor must destroy the enemy outposts. However, one can no longer fast travel to those outposts. Get in there the old-fashioned way and eliminate the raiders.

To establish a raider outpost, the player character must speak to Shank. They will then be given the option to capture a new outpost or intimidate a settlement to supply nearby outposts. Both jobs will allow the use of violence or intimidation. When violence is chosen, the player character will be joined by three gang members of their choosing and must kill or cripple the settlers and their Minutemen backup. Intimidation can be used on settlements with named non-random NPC settlers, where the player character can threaten or bribe the residents.

Take caution when establishing the first raider outpost as this will drop Preston Garvey's affinity to the lowest level, even if he is not present. Therefore, it is advised to move him away from any desired settlements before establishing any raider outposts or become the overboss of Nuka-World prior to becoming the general of the Minutemen.

It is not possible to establish a supply line between two raider outposts, but all raider outposts are automatically linked to each other, so it would be unnecessary. It is also not possible to establish a supply line between a raider outpost and a regular settlement, so a separate supply of building materials will be required for raider outposts.

In order to convert the outposts back into Minutemen settlements, one will need to kill all of the raiders at that outpost. If the raiders go hostile, then the turrets will also go hostile as well. Be warned, that once all the raiders at that outpost are killed, the Sole Survivor will be declared an enemy to the Nuka-World raiders, thus losing control of all outposts and failing any incomplete Nuka-World raider related quests, starting Open Season, the quest where the Sole Survivor must execute the Nuka-World raider gang leaders (Nisha, Mags Black, William Black, and Mason) in order to put an end to slavery to the traders of Nuka-Town.

Necessities and dependencies
These stats need to be maintained to sustain or stagnate the growth of a settlement. Each necessity would also act as a dependency on other necessities; i.e. people need water, food, beds, and protection to live and thrive.

People



 * The population of the settlement. People are required to collect from resource units and man objects the Sole Survivor builds. Each settlement has a default max population of 10 settlers plus each point of Charisma the character has, which has a base max of 21 (10 from leveling and +1 from bobblehead) before factoring in extra charisma from armor and consumables. A radio beacon is generally required to attract more settlers, but one can send companions to settlements and can recruit a few non-companion characters to join, alternatively, settlers can be told to "move" from an already populated settlement.
 * Provisioners will still count to the population of a settlement, but only to the one that they were sent from.
 * Increasing populations and lower happiness scores will increase the time for new settlers to arrive using the radio beacon.
 * If more than four settlers are either unassigned or assigned to provisioner jobs, no more settlers will arrive on their own.
 * Dependencies: water, food, beds, defense, radio beacon

Food

 * How much food the settlement is producing. Increased by placing food resources.
 * Every 24 hours, independent of the timer for the food resource to be manually harvestable by the player character again, every food resource assigned to a farmer will generate one food item of the same type for every whole unit of food production of that type, which will be added to the settlement's workshop inventory.
 * Food will not be automatically produced at any settlement whose workshop contains more than 10 food items (including items that cannot be produced by settlement resources, like meat, gumdrops, etc). This cap on production increases by 1 per settlement population.
 * Dependencies: people, water. Crops will die without water.

Water

 * How much water the settlement can produce.
 * Single pumps produce small quantities of water; large scale water manufacturing is possible, but the purifiers (both normal and industrial grade) require materials and an open body of water in which to operate.
 * Every 24 hours, a settlement with a non-zero population will produce 1 purified water per unit of water production. This water will be stored automatically in the settlement's workshop.
 * Water will not be automatically produced at any settlement whose workshop contains more than 5 drink items (including items that cannot be produced by settlement resources, like dirty water, alcohol, etc). This cap on production increases by 1 per every 4 units of settlement population.
 * In Survival mode, water resources can be used by the player character to satisfy thirst and convert empty bottles to purified water.
 * Water pumps, both large and small, are susceptible to damage during raids and may need to be repaired in case of an attack.
 * Dependencies: power (only with water purifiers)

Power

 * Generated power is used to operate anything that needs electricity, including lights and defense turrets.
 * Power is required for some turrets, traps, lights, and furniture items.
 * Generators are connected via wire. Each wire costs 1 copper unit, regardless of length. Distance is limited and power pylons and relays, or multiple generators, may be required to power larger grids.
 * Repair generators after attacks, they are the main target
 * Dependencies: n/a

Defense

 * Measures the apparent defensive improvements the settlement has based on settlement buildings with defense ratings. Only provided by defenses built at a workshop; mines do not count toward settlement defense rating, even though they can destroy attacking forces if the player character is also present. Some creatures able to be captured using cages (featured in Wasteland Workshop) also add to the defense rating, such as deathclaws and yao guai.
 * Defensive improvements range from fortifications, which require assigning a settler as a guard, to autonomous turrets (small turrets run on their own power, while larger ones require separate power sources), as well as an assortment of traps.
 * Settlers can be provided with weapons and ammunition, and arrive in settlements with their own. As long as they have at least one unit of ammo in their inventory, they will not run out. Settlers themselves do no contribute to the defense rating, rather, well armed settlers will be better at repelling attacks, provided the Sole survivor is present.
 * One can build a siren near a guard post and the guard will activate the siren upon spotting an enemy. The siren will alert settlers in the area that enemies are approaching, and they will move towards the siren to help defend.
 * There is also a wandering salesman named Gene who sells junkyard dogs that provide 5 defense.
 * Enemies a settlement will face is based on the level range of the cell the settlement is located in on the map. In general, settlements located further south will face tougher enemies.
 * Each point of defense lowers the chance of an attack by 1%.
 * Each population unit lowers the chance of an attack by 0.5%, in addition to any other defensive value the settler provides.
 * Each unit of food and water production at the settlement increases the chance of attack by 0.1%.
 * Each edible and/or drinkable item stored in a settlement's workbench increases the chance of attack by 0.1%.
 * The minimum chance of an attack upon a settlement per day is 2%, regardless of defenses. The maximum chance is unknown but assumed to be 100%. Whatever the chance is, a settlement cannot be attacked if it has already been attacked in the last 7 in-game days.
 * The defense values do not directly correlate with actual combat efficiency. An Mk. 5 machine gun turret can kill enemies several times faster than an Mk. 1 heavy machine gun turret but will contribute less to the settlement defense value.
 * Dependencies: people, power (with certain turrets and traps)

Beds

 * The number of beds in the settlement. The settlement needs one bed per settler to keep the settlers happy.
 * Settlers normally assign themselves to available beds automatically upon arrival or as beds are built. It is possible that settlers will not assign themselves to a bed unless the total needs for all settlers are met. After additional beds are built, it may be necessary to manually assign all settlers to individual beds.
 * In some settlements with preexisting beds, such as Abernathy Farm, Tenpines Bluff, and Covenant, settlers often require manual bed assignments. Others such as Sunshine Tidings co-op work automatically. Problem settlements may show a proper amount of beds in the building overlay, but settlers may comment on the bed situation and settlement happiness will be negatively affected.
 * Even in settlements that do not start with preexisting beds, it is possible for happiness to suffer without settlers complaining, simply because they have not automatically assigned themselves to beds. Manually assigning beds to ensure each settler has a bed is a good way to ensure there are no hidden negatives dragging down happiness.
 * Scrapping/disabling/ignoring all preexisting beds in a settlement and building new ones in their place may help avoid this problem from the start. To disable a bed on PC, enter the console, click on the preexisting bed, type, then exit the console and build a new bed in its place. This can also be done to a bed that will not accept manual assignments. Otherwise, building additional beds equal to the preexisting ones may be required.
 * To quickly identify all settlers without a bed, sleep or wait until midnight when settlers other than guards and provisioners will go to bed. Any others left awake require manual assignment.
 * Assigning a job to a settler in a problem location may cause their bed assignment to be lost, so assign jobs before manually assigning beds.
 * Dependencies: n/a

Happiness

 * This is the morale of the settlement. Increasing a settlement's happiness will increase the productivity of its settlers. One may lose control of a settlement that is very unhappy.
 * Happiness primarily correlates with providing for the needs of the settlers. Keeping settlers happy is as simple as keeping all the other settlement resources (food and water, beds, and defense) at sufficient levels. Each of these needs to be at least equal to the number of settlers; power itself does not affect happiness but is required to operate more efficient machinery.
 * The displayed happiness value is calculated by adding together all happiness points and dividing by the total population.

Size

 * Shows the number of objects that have been placed by the player character within the settlement, as well as the maximum amount of objects that can be placed through the Settlement interface. Every existing or user-built item takes up settlement size. If the settlement size is maxed, other objects within its boundaries must be scrapped in order to place more structures.
 * It is possible to bypass the in-game size limit of settlements by dropping items to the ground and scrapping or storing them manually. Each scrapped item refunds a small number of allotment points allowing to build more objects. Placing large amounts of objects in any settlement may cause frame rate issues and lag while in that settlement.
 * With the Local Leader perk, food/water and junk resources can be shared between settlements connected by a supply line allowing the player character to quickly build out new settlements or even specialize them.
 * Dependencies: n/a

Settlement attacks
Once the Sole Survivor has control of a settlement, they will need to defend it from attacks by raiders, super mutants, and other hostiles. Impending attacks will be reported by the Sole Survivor's Pip-Boy, showing up as a miscellaneous objective. The Sole Survivor can travel to the settlement to deal with the attackers if they so choose. Otherwise, the attack will be resolved off-screen, with the results being reported by the Pip-Boy. Failing to defend the settlement successfully will cause damage to various buildings, as well as reducing happiness. Increasing the defense rating of the settlement reduces the chance of an attack occurring, as well as increasing the chance of a successful defense. Companions residing at settlements, as well as robots with Automatron can assist the settlement if attacked.

Several Minutemen quests also include scripted settlement attacks. These attacks use similar mechanics, but with greater rewards (and sometimes greater consequences for failure).

Damage
During an attack, the attackers can damage various settlement objects including turrets, water pumps, purifiers, generators, and crops. If the attack is resolved off-screen and results in a failure, damage will be applied to a random selection of settlement objects. Settlement-related quests will also apply scripted damage to settlements from time to time. This damage will repair itself over time; the Sole Survivor can also use the workshop to repair settlement objects manually using some of the materials required to build the object.

Damaged settlement objects will no longer perform their functions. For example, a damaged turret will not fire, nor will it contribute to the settlement's defense rating. Damaged crops, purifiers, and pumps will not contribute to food or water supplies. This can result in a significant reduction in happiness if a settlement is subject to frequent attacks, so building up settlement defenses is crucial to maintaining a happy settlement.

Attack chance
The chance of a settlement being attacked is calculated as follows:

$$\text{Base} = \frac{\text{Food} + \text{Water}}{2}$$

$$\text{Reduction} = \frac{\text{Population}}{2} + \text{Defense}$$

$$\text{Attack chance} = \max(\text{Base}% - \text{Reduction}%, 2%)$$

The attack chance can never go below 2%. The food and water in these formulas also include that stored in the workbench, meaning that the attack chance may increase over time for settlements with excess production.

For example: If a settlement has 5 food, 6 water, 2 defense, and a population of 5, the attack chance is calculated as follows:

$$\text{Base} = \frac{5 + 6}{2} = 5.5$$

$$\text{Reduction} = \frac{5}{2} + 2 = 4.5$$

$$\text{Attack chance} = \max(5.5% - 4.5%, 2%) = \max(1%, 2%) = 2%$$

Behind the scenes
During a game jam session at Bethesda, programmer Michael Dulany developed a system for building and furnishing player bases, which worked its way into Fallout 4 as the settlement workshop system. It was on the verge of being cut for a long amount of time during development, but remained in the game and became one of its tent-pole features.

Bugs
This is a fundamental limitation of the simulation engine, so there are no methods to permanently prevent this from occurring, though several workarounds and temporary fixes exist:
 * When away from a settlement, the Pip-Boy's workshop section on the data screen may show incorrect values for a settlement's statistics, such as water and beds. This occurs when the player character enters an exterior cell close enough to a settlement such that only a subset of the settlement's exterior cells are loaded into the simulation engine. The result is that only those objects in the loaded cells are included in the statistics. Unfortunately, the settlement will experience the expected negative consequences of this, such as the happiness score dropping, and settlers may become unassigned from their beds. The effect will be more noticeable in larger settlements, such as Sanctuary Hills, which are composed of a larger number of exterior cells, and in the case of Spectacle Island, this can occur without even leaving the island. It will not affect settlements which only consist of a single cell, such as County crossing.
 * Returning to the affected settlement and opening the workshop should correct the statistics. In the case of Spectacle Island, you may have to travel to the center of the island to ensure all the cells have loaded.
 * Replacing all pre-existing beds in a settlement may prevent settlers from becoming unassigned from or not assigning themselves to these beds. On PC, if scrapping is not possible, select the bed to be removed in the console and using commands and then  will permanently remove the selected beds.
 * One can fix this by group selecting preexisting beds and moving them onto a floor. Scrapping or storing the floor will then delete the bugged bed. This feature is disabled after 1.6 patch.
 * Manually assigning all settlers to a bed using the command option in the workshop menu may prevent settlers from becoming unassigned from their beds.
 * If a distress pulse is dropped on the ground in a settlement and then scrapped using the building screen it will permanently emit a distress signal.
 * After choosing 'barter' at a user-created settlement shop, the trade window may open to two blank lists (player character and settler inventories are empty), where the settler has 0-6 caps and nothing can be done except exiting.
 * Exiting the trade menu, selecting the 'all items' category in the Pip-Boy, and then retrying barter may resolve this bug.
 * Settlers with a coded routine may continue it at the expense of an assigned job. This occurs mainly with original settlers from before a settlement is unlocked and some named settlers. Examples include Sturges or Marcy Long rarely being present at a store if assigned (though still bartering from wherever they are), robots at Graygarden tending plants regardless of assignment, and original settlers in Greentop Nursery assigned to guard posts spending time sitting in chairs inside the house, while new settlers assigned the same roles do not. For assignments like guard duty where being in the correct location matters, a new settler may be a better choice.
 * When fast traveling to a settlement, settlers may be seen standing on the roofs of natural or player character-built structures with no way of getting to the top of them.
 * Fast-traveling to the settlement again should make them return to the ground.
 * Beds that are under a cover (even in an entirely enclosed building) may not be recognized as such, impacting settlement happiness.
 * If a switch or generator is stored or scrapped when the wire is being pulled out, sparks may remain hovering and cannot be removed.
 * Settlers assigned to stores (except clinic) placed above the water at Nordhagen beach, refuse to engage in dialogue.
 * Simply moving those emporiums away from the water and placing them on a dry surface resolves this.
 * Sometimes if you re-assign a settler from food production to a new task, all other settlers doing food production stop working on food, and food production drops to zero.
 * Normally, when assigning a settler to a crop plant, the game will automatically assign the settler to any other untended plants at the settlement. Sometimes this does not happen, and only the individual plant is assigned. Restarting the game (not reloading a save) will fix this.