Intelligence

Intelligence is one of the Primary Statistics in the SPECIAL character system. It represents knowledge, wisdom and the ability to think quickly. A high Intelligence plays an important role for any kind of character.

Fallout, Fallout 2 and Fallout Tactics
Modifies: the number of new Skill Points per level, dialogue options, and many skills.

One of the unique qualities of Fallout and Fallout 2 was the difference in gameplay, specifically dialogue, if you decided to create a low intelligence character. The many retarded words your character may say, is "wubba-wubba?". If you have a low intelligence, you will make no real progress in the world, since Killian, and many other NPCs will just ignore you.

Fallout 3
Modifies: Medicine, Repair, and Science skills, as well as the number of new Skill Points per level.

The base number of skill points gained per level is 10+Intelligence. Skill points gained for raised intelligence are not retroactive for past levels, so increasing this primary stat early if at all is the best. Also, temporary modifiers to intelligence (e.g. from Night Person or Button's Wig) do not affect the number of skill points gained.

One of the methods to maximize skill is to place 9 points in intelligence at character creation, then rush to Rivet City Science Lab and grab the bobblehead once you are out of the vault at level 2. The easiest way to get there is by the west side of river (don't forget to ignore all npcs, so that you don't gain a level accidently). After the Citadel, you can swim around Jefferson Memorial to reach Rivet City. Another strategy is to swim the entire route to Rivet City, thereby avoiding all encounters once you reach the water. If you start the Contract Radiation Sickness objective for the Wasteland Survival Guide quest beforehand, you can Fast Travel back to Megaton afterwords and have your radiation healed for free.

It should be noted that with Comprehension, Bobbleheads, and the base skills, it is entirely possible to reach the magic total of 1300 skill points required to maximize all skills with a merely average Intelligence, even without Educated.

Ways to increase Intelligence

 * The Bobblehead - Intelligence is in the Rivet City Lab.
 * The Night Person Perk increases your Perception and Intelligence when the sun is down.
 * The Intense Training perk will allow you to increase your Intelligence (or any other S.P.E.C.I.A.L. stat) once for each time that you take it.
 * Lincoln's Hat and Button's Wig each give +1 to the stat. This does not affect skill points gained at level up, but does increase the relevant skills.
 * Mentats give a temporary +5 to the stat. This does not affect skill points gained at level up, but does increase the relevant skills.