Intelligence

Action is the real measure of intelligence.

Intelligence measures the character's intellect and scales with Skill Points making character more versatile and able to handle a wider range of challenges. Each point of Intelligence represents 3 SP per level. If Character have Gifted then is 2 SP per level for each Intelligence, also other sources then base SPECIAL don't count to SP per level. (Mentats or Armor Perks).

IN also scales with experience earned on worn gear +3%, +1 Lethal Damage and more.
Full list in S.P.E.C.I.A.L.

Also you cannot become Slaver with less than 4 intelligence.

Drugs that affect Intelligence

• Mentats +2
• Roentgen Rum +1

• Cannibal Drugs Brain +2

Tips

The number of Skill points you will earn at each level is important and considerably affect a character's final outcome. So it might be vital for a crafting character to have 10 in Intelligence, for example, to be able to have all the skills up as fast as possible. Support Perk Educated adds +2 skill points when You gain new level.

Most quest requires 4 IN to start and finish them. But most quests can be done with bonus from Drugs or Armor Perks bonus.

If you are an experimented fallout player, you can calculate the exact number of skill points you will need for your character, so you can choose the value in intelligence which you will really need and to optimize the rest of your build.

Serious PVPers tend to leave intelligence at 2 or 3, sacrificing the high amount of skill points gained per level so they may instead invest the SPECIAL points into endurance, agility, luck, or perception. It is suggested not to leave intelligence at 1 unless you're experienced with character builds, as it may be difficult, if not impossible, to meet the skill requirements for the perks you want.