Mechanics

Fallout 4's systems divide neatly on one question that nobody asks until it has already cost them something: does this thing keep running when I am not looking at it? A workbench does not. It sits inert until you walk up and press a button, and it will wait forever. A settlement's happiness rating does not wait. Neither does Survival mode's hunger timer, and neither does the decision you made three quests ago in Far Harbor.

Sorted that way, the nine systems we cover fall into four groups, and the grouping tells you which ones you can safely ignore for twenty hours and which ones are quietly accumulating a problem.

Systems that wait for you

The four build-and-tinker systems are entirely under your control, which is why they are also the four you can put off indefinitely. The catch is that they compound: every hour you spend not scrapping is an hour of components you do not have when you finally want to mod a weapon.

Crafting is technically optional and practically not, because nothing you find in the world matches what you can build. The system is broad rather than deep: weapons, armour, Power Armor, chems, food and resource items are all craftable, and each category has its own bench, so weapons go to Weapon Workbenches and Power Armor goes to Power Armor Stands. The learning curve is in the mods, not the recipes.

Scrap farming is the half of crafting nobody plans for. Base components do not exist in the world as components; they exist inside desk fans and hot plates and duct tape, and getting them out is a habit rather than a task. Our guide's efficient junkman section is the part worth reading first, because the difference between hauling everything and hauling the right things is most of the time cost of the entire crafting system.

Terminal hacking is the one system in this group that is a genuine puzzle rather than a resource loop, and it is solvable rather than lucky once you understand the feedback. A wrong password returns a likeness value, and that number is how many of its letters sit in the same position as in the correct password. Guess Marks and get a likeness of 2, and the answer shares two letters with Marks in the same slots, which is enough to point at Names. Every failed guess narrows the field; the mistake is treating them as random attempts.

Workshop items is the largest single reference we have for the settlement layer, running to twenty categories from picket fences and chairs through generators, connectors, turrets and water items to the five kinds of store. What the list is actually for is the prerequisite column: some items you can place the moment you enter build mode, and others are locked behind something you have not done yet.

Systems that do not wait

Three systems keep score while your attention is elsewhere, and all three are capable of presenting you with a problem you did not watch develop.

Settlement happiness is the clearest example, because the target is a specific number and reaching it earns the Benevolent Leader achievement. The advice in our guide is unusually blunt about the setup mattering more than the upkeep: clear out everything that was standing before you arrived, and pick a location with plenty of prebuilt housing so you are not building beds from nothing. It also names two settlements to avoid for this purpose, Sanctuary and the Railroad settlement, which is the kind of thing worth knowing before you invest fifty hours in the wrong place.

Survival mode debuffs run on a real clock and share one mechanic that makes them easier to reason about than they first appear: every debuff in the mode reduces your maximum Action Points. Hunger, thirst and the various ailments differ in how you cure them, but they are all subtracting from the same pool, which means your AP bar doubles as a status readout. The exception on that page runs the other way. Well Rested, from sleeping in a bed you own, is a buff worth +2 Endurance, +2 Agility and 10 percent extra XP.

Random encounters fire as you move rather than as you choose, and our guide sorts them into eight types, including static and fluid encounters, campsites, chokepoints, treasure hunts, companion encounters and the ones where two groups fight each other while you watch. Knowing the categories is mostly about knowing when to intervene: a chokepoint encounter is a fight you are walking into, and a watch-them-fight encounter is one you should let finish first.

The system already decided

Far Harbor's endings belong in a category of their own, because by the time you can see the outcome the inputs are behind you. Two quests do most of the work, Cleansing the Land and The Way Life Should Be, and two other factors adjust it: how many optional missions you completed and how good your persuasion is. The decision about Avery in particular can still be changed depending on those two, which makes optional Far Harbor content genuinely load-bearing rather than filler.

If you are going into Far Harbor with an ending in mind, this is the page to read before the quests rather than after them. The Children of Atom line is the other half of the same equation.

The system on nobody's clock

Easter eggs are the one thing here with no timer at all. They were placed before you arrived and they will still be there at level 60, which makes them the safest content in the game to postpone. Our guide runs from film and game references, including a Donkey Kong nod and a Jawa death scene, through to the one that is a functional reward rather than a joke: the Alien Blaster from the crashed UFO, which needs you at level 20 or above and sends you from Greentop Nursery west toward Old Gullet Sinkhole to trigger the event.

That level requirement is the only clock in the section, and it is a floor rather than a deadline.

Which one to learn first

If you are early in a run, learn hacking and scrap farming, because they are cheap to learn and everything else in this bucket depends on the components you are not currently collecting. If you are mid-run and building, read the happiness guide before you commit to a settlement rather than after. If you are on Survival, the debuff page is the only one here that will actively kill you if ignored.

Where these systems point next is mostly the locations bucket, since the settlement systems need somewhere to run, and the items bucket, which is what crafting consumes. The builds guide covers which perks make each of these systems cheaper to use.