"You're Special" is a book found in Sanctuary Hills, which will increase one of your primary stats.

Normally you cannot exceed 10 points in any of the primary stats, but if you consume an item which temporarily lowers one of those SPECIAL stats, you can boost your stat to 11. Picking up the corresponding bobble-head afterwards will raise the SPECIAL stat to 12.

Endurance, Agility and Luck cannot be raised to 12, unless Survival Mode is active.

Note: The game will only allow you to activate Survival Mode once, if you use it now, deactivating it will lock you out of the difficulty permanently.

Highly Recommended, especially if you're playing a melee character (an unconventional build for Survival but I won't judge). Even even if you're not playing melee, the extra 10 weight is a nice quality of life considering your total carry weight is reduced by 125 when playing Survival.

Functionally useless, since V.A.T.S. accuracy caps out at 95%. If you like Perception for the V.A.T.S. - why are you playing Survival?

Highly Recommended. It may be the single best stat for Survival. It will give you extra HP, which could be the difference between dying or not, and scales more the higher your level is.

But more importantly, you can sprint for further distances at a time. If you have 12 Endurance, and 5 agility, you can squeeze out an extra 2 seconds of sprinting with full action points (compared to 11 Endurance). Which might not seem like much, but considering there is no fast travel, you will end up saving a significant amount of time in the long run.

Probably not useful for most players. The extra settler doesn't count for much, and depending on how you play, the extra caps might be useful, but I doubt many people are playing this game as an economist. At 11 Charisma you can pass all skill checks safely, 12 is not needed.

Not recommended. Extra XP isn't as good as it seems in the long run. Enemies level with you, and eventually, once you've picked up all the perks and weapon mods which increase your damage, there is no more progression for you, but the enemies keep getting stronger. If you don't mind turning off Survival later, to dial back the difficulty, or want the most brutal experience possible, then go for gold.

Functionally useless. If you're looking to get more sprint power, you'll get more of it from the extra point of Endurance. If you like Agility for the V.A.T.S. - why are you playing Survival? It does help slightly with Sneaking, but I don't know how much. I have to assume the difference between 11 and 12 is not noticeable.

Not recommended. The extra items and caps might help in the early game, but that's about it. If you like Luck for the V.A.T.S. - why are you playing Survival? If you want it to add another Perfectly Preserved Pie to your collection, you've reached the true meta, congrats.

Consumables
Day Tripper

Survival Mode
Sleep = Overtired > Weary > Exhausted > Incapacitated

Consumables
Fury
Drugged Water

Survival Mode
Water = Thirsty > Mildly Dehydrated > Dehydrated > Severely Dehydrated

Consumables
None

Survival Mode
Hunger = Peckish > Hungry > Famished > Ravenous > Starving

Consumables
Daddy-O

Survival Mode
Hunger = Hungry > Famished > Ravenous > Starving

Consumables
Alcohol

Survival Mode
Thirst = Parched > Thirsty > Mildly Dehydrated > Dehydrated > Severely Dehydrated

Consumables
None

Survival Mode
Sleep = Weary > Exhausted > Incapacitated

Consumables
None

Survival Mode
Thirst = Mildly Dehydrated > Dehydrated > Severely Dehydrated
Hunger = Famished > Ravenous > Starving
Sleep = Weary > Exhausted > Incapacitated

There are a lot of misconceptions, so I tested each myself.

ADDICTIONS will NOT allow you to increase your SPECIAL stat with "You're SPECIAL"

Addictions worked in a previous version of the game, which is why you might find people still claiming addictions will allow you temporarily drop your stats to pick the book up.

I tested the following addictions personally.

• Alcohol
  
• Buffout
  
• Calmex
  
• Daddy-O
  
• Day Tripper
  
• Fury
  
• Jet
  
• Med-X
  
• Mentats
  
• Overdrive
  
• Psycho
  
• X-Cell

Also, being over-encumbered (on survival) doesn't count, despite losing relevant stats.

It probably isn't worth trying to get a SPECIAL stat to 12 at the very start of the game, unless you're going for INTELLIGENCE (though I caution against it for reasons aforementioned).

My advice is to leave "You're SPECIAL" and all SPECIAL bobble-heads in place, until none of the perks available are useful to you. This happens VERY late into the game, and the benefits of the extra SPECIAL stat are practically useless at this stage.

This guide was primarily written for people who want to min-max for the sake of min-maxing, or just because you enjoy exploiting bugs without breaking the game.