Hey you! Yes, you! You're special, do you know that!? Well, your Fallout 4 character is anyway! The SPECIAL statistics control what perks your character can learn as you play the game, so it is extremely important that you have an idea of what you want your character to do when you pick your SPECIAL stats. To help you out and give you a general idea of what is worthy of your time, check out the SPECIAL stats below.
Note: At the start of the game, you will have to pick your SPECIAL skills, but note that you will get a chance to change these picks later on, so the first time isn't a "final choice" situation.
Note: Unlike recent previous Fallout games, Fallout 4 has no level cap. Realistically, this means your SPECIAL picks are going to dictate what perks you can get access to quickly and won't ever "lock you out" of anything whatsoever.
With those notes out of the way, let's go over each of the SPECIAL categories so you know what each of them do (along with noteworthy perks in each category).
Strength is pretty-much a must if you are going for Unarmed or Melee builds. Thankfully, both of those perks come very early with Rank 1 and Rank 2 respectively. People wishing to specialize in Heavy Weapons will want to reach Strength Rank 5 in order to start adding on damage modifier to their weapons.
If you are planning on modding armor or melee weapons (Armorer in particular is highly recommended at some point in the game), you will want the Armorer and Blacksmith perks at Ranks 3 and 4. Blacksmith is really only for die-hard Melee builds, but Armorer will help out any player and should be taken and invested into at some point. Ballistic Weave breaks the game to a large degree, and it will require ranks of Armorer to add this stuff to your clothing, perhaps tripling your defense, making the Toughness perk entirely redundant.
Further perks beyond these are all very situational, although it is hard to deny that the Rank 6 Perk, Strong Back, is great for your character's quality of life, and a must-have for general pack-rattery. The last rank in Strong Back even allows you to fast travel when over-encumbered which is, quite frankly, an amazing ability to have. Combine that with a good amount of agility to really clean places out quickly.
Perception is another trait that it is helpful to invest in, especially if you plan on using VATS with any sort of consistency. However, it is highly recommended you at least get to Rank 4 in Perception for the Locksmith skill, as there is nothing better than being able to pick you way into places (or pick locks for various goodies). Lockpicking will literally help you out the entire game and should be invested into whenever you are given a chance.
Overall, Perception has quite a few great ranks in it, although most of them require significant investment. The Rank 1 Skill, Pickpocket, blossoms more as you level it up as you will eventually be able to steal equipped items from people which is quite noteworthy. You will also need it leveled up to rank 2 for the "Prankster's Return" trophy (although you can just save up some perks, buy that, use it for the trophy, and re-load). The Rank 2 Rifleman skill is great for non-automatic rifles as it ups your damage considerably as you level it (never a bad option). In fact, it's arguable that non-automatic rifles are the only weapons you'll need in the long run, as they cover all combat situations: close range (Combat Shotguns), medium range (Combat Rifle/Assault Rifle/Laser Rifle/Plasma Rifle) and long range (Hunting Rifle/Gauss Rifle).
The Rank 5, 6 and 7 skills are all good situationally, but unless you are a grenade madman or plan to only play during night-time hours it's hard to justify putting points into them early at all. However, to get to some of the better Perception perks such as Sniper, Penetrator and Concentrated Fire you will have to invest a lot of points into Perception, making them skills you will quite honestly want to work towards later in the game instead of investing into right away.
Note: You will find the Perception Bobblehead fairly early in the game, and picking it up will give you a bonus of +1 Perception automatically. Keep this in mind as you assign points, just in case you are wavering on your last point assignment.
The Endurance skill tree is (surprise) all about survivability, boasting quite a few skills that make it harder for you to get hurt and help heal you easier. The Rank 1 Toughness skill is straight-up damage resistance. The Rank 3 skill, Life Giver, is also note-able for giving you more health and a slow auto-regeneration ability at level 20 if you invest fully into it (which is fairly early into the game and will undoubtedly save you on medicine and food). It won't save your life in a fire-fight, but it will frequently negate the need to use a Stimpak between fights.
The rank 5 ability, Aquaboy/girl is very tempting, but there honestly isn't too much traveling around in water during the game. It is mainly handy for short-cuts around bodies of water to be quite honest, so while it is tempting you can likely find something better to invest in (it makes a good "quality of life" skill later in the game).
Beyond rank 5 you have a number of skills that are very handy, but also situational. Finding and carrying around Stimpaks and using cooked food will help you out as well as most of these perks, making most things beyond rank 3 in Endurance more of a luxury than a necessity. If you are cutting anywhere for extra points, this means Endurance is a fairly good candidate to steal from but beware: Save often as your lower Hit Point total can get you into trouble now and again.
Can you say "Dump Stat?" Charisma has some great skills in it, but almost none of them directly help you out during a fight. Charisma does affect dialog options and can get you desired results during speech checks, but considering the fact that you can (much more often than not) walk away during a conversation and re-enter it, as well as quicksave before attempting speech checks, the need for a naturally high Charisma score is very much lessened. Add on the fact that you can find and equip Charisma-boosting gear and use various drugs (like Day Tripper) to instantly and easily gain 8+ Charisma in seconds seals the deal; you never need to boost Charisma for any dilogue checks in the game.
All that said, there are some note-worthy perks here. If you hate companions, the rank 3 perk Lone Wanderer is fantastic (and even works with Dogmeat). The rank 6 perk, Local Leader, is also very handy for building and maintaining settlements, as supply lines are so very useful as you craft and build multiple locations. It along with the rank 1 perk, Caps Collector, are also needed to build certain structures (stores) at your settlements. Lastly, Wasteland Wanderer gives you the chance to pacify (or even command) some of the strongest critters in the game, including Deathclaws, Mirelurks and Super Mutants, which, while not necessary or terribly relable, can simply some fights. So while there are some things here worth investing in (especially for builders), most of it is highly situational and best looked into during the late-game.
Much like Perception, Intelligence is pretty much a required stat, and not just due to the fact that it ups your experience gained. This is mainly due to the rank 4 perk "Hacker", which will serve you all game long by letting you hack various terminals around the map to access secret areas and various goodies. Much like Locksmith, if you want to be able to get into any area in the game you pretty much must invest into this skill and level it up when you can.
Intelligence has a variety of other extremely useful perks as well. The rank 1 perk, V.A.N.S., guides you to objectives but is more of a luxury than anything (plus you have this guide!). The rank 3 perk, Gun Nut is fantastic as it lets you mod weapons (firearms) and greatly enhance them, which often translates to much greater damage. That is one perk you will want to jump on if you use firearms at all! Okay, so you don't really need Gun Nut, as you can find weapons with the mods on them (which you can remove and put on your weapon of choice), but you will be able to build these mods with Gun Nut far, far earlier than enemies will drop them, and waiting around for a fortuitous drop just isn't ideal. Gun Nut will make you over-powered (along with a weapon perk like Rifleman) for a good stretch of the game, and in general just makes killing things that much simpler.
Ranks 5 and 6 are both fantastic overall as well. The rank 5 skill, Scrapper, is more of a "quality of life" skill that rewards you with greater bounties for scrapping items (which helps) but the second rank will straight-up highlight containers that have items you've tagged for search, which is immensely useful. The rank 6 skill, Science!, is the "Gun Nut" equivalent for energy weapons and also comes into play when modding Power Armor as well as building certain items at your settlements. A very important skill for building and modding things.
Beyond rank 6 you start running into some very situational perks. Chemist can be good if you are a druggie and Nuclear Physicist is handy for fusion cores, but honestly you can find better perks to spend points in. And Nerd Rage, the rank 10 perk does you no good unless you let your health dip down to below 20%. You can do better.
Agility is one of the best SPECIAL stats you can invest in in Fallout 4, right up there with Perception, Intelligence and Luck. Ranks 1 and 2 are both weapon perks with Gunslinger upping non-automatic pistols and Commando upping the damage of automatic weapons, both of which may help you out depending on your build.
More importantly, ranks 3 and 7, when combined, can turn you into a sneaking powerhouse. Rank 3, Sneak, makes you harder and harder to detect and actually does function properly throughout the game. It also provides bonuses such as making you unable to trigger traps and enemy mines (which there are plenty of throughout the game). Combine that with rank 7, the Ninja perk, and you can string together a number of sneak attacks to completely annihilate your opponents. This works best with silenced weapons and/or unarmed or melee builds (so you don't give your position away).
Speaking of silenced weapons, the rank 4 perk, Mister Sandman, does give a bonus to silenced weapon damage, and since with the Gun Nut perk you can silence almost any weapon (even shotguns!) in the game, this could provide a handy boost to any sneaky guns build. The rank 5 skill, Action Boy/Girl, is also pretty much a must-have if you plan on using VATS at all as Action Points regeneration is just... so very useful.
Finally two more perks worth pointing out. The first is a very tempting but awesome perk for any melee or unarmed build character: the rank 9 perk "Blitz". This gives you the ability to target enemies from a distance using VATS - essentially warping you over to them so you can deliver damage (and when I say "warping", I mean it: you can warp upwards and downwards even). This stacks extremely well with both Sneak and Ninja and is especially useful for unarmed and melee characters as the sneak attack bonus from Ninja are even higher than firearm bonuses. The second perk worth noting is the rank 6 perk, Moving Target. This gives you very decent defense bonuses when sprinting, which can really help melee and unarmed builds. Worth considering, especially if you are reaching up for Blitz anyways.
The last few perks, Quick Hands and Gun-Fu (ranks 8 and 10) are okay, but again situational. Quick Hands is a luxury that can wait forever while Gun-Fu is handy only when there are multiple enemies around and you have the luxury to cycle through them. Gun-Fu has very good damage modifiers, but getting there is awfully expensive for something you may not even use all the time.
You either have it or you don't! There are plenty of "must-have" perks here, so many, in fact, that Luck is probably the most important SPECIAL attribute in the game. What's more, many of the Luck perks synergize with each other, meaning the more points you have in Luck, the more perks you invest in, the stronger you'll be. Let's get to it, then.
The rank 1 and 2 perks - Fortune Finder and Scrounger - are helpful but luxury perks: you can get by without either of them especially if you spend your caps wisely and vary up your weapon choice. Bloody Mess also makes a return from previous Fallout games and provides entertainment and bonus damage at rank 3. Probably not a perk you'll care to invest in early on, but it's still a nice, pure damage boost that everybody can eventually enjoy.
And then you have a number of random perks, that undoubtedly will help you but you have no control over. These include Mysterious Stranger, Idiot Savant, Grim Reaper's Sprint, Four Leaf Clover and Ricochet (ranks 4, 5, 8, 9 and 10 respectively). Each of them are great for either protecting you or providing more damage (or criticals), but triggering them are all up to luck. Idiot Savant in particular deserves some explanation, as bonus XP is nothing to sneeze at. It does require, or at least processes more often, with low intelligence though so keep that in mind. It can also process when you finish a quest as well, meaning ridiculous chunks of XP can be gained at times. It will almost certainly pay for itself in the long run, so getting two ranks in it is worthwhile for any build that has an Intelligence score of eight or lower.
Critical Hits are already a difference-maker even with no Luck, but the rank 6 perk, Better Criticals, gives you much more bang for your buck. Nothing can really beat the rank 7 perk though, as Critical Banker is just over-powered. Leveling it up to the max lets you save (bank) up to four Critical Hits to be used whenever you want. Let's face it - that is basically a gigantic "I Win" button in your back pocket. Especially with perks like Better Criticals, Grim Reaper's Sprint and Four Leaf Clover... with their powers combined you'll become a walking agent of VATS-y destruction. Throw in some armor that boosts your Action Points and use a VATS-Enhanced or Lucky legendary weapon, and you'll become all but unstoppable.