Fallout 3 primary statistics

Primary statistics in Fallout 3 are numerical representations of characters' inherent abilities. In the SPECIAL character system, there are 7 primary stats. Their first letters form the name of the system itself.

Overview
The minimum for each primary statistic is 1 and the maximum is 10. Each statistic directly modifies certain derived statistics. In addition, every skill is tied to a primary statistic. As a result, each point added to a primary statistic results in a bonus of 2 points to the associated skill(s). The only exception is Luck which only adds 1 point; in turn, all skills are affected by this stat. Some perks require certain minimum attribute values as well.

Increasing attributes
There are multiple ways to increase your attributes after character creation. They can be increased permanently by taking the Intense Training perk at level-up (which can be taken up to 10 times, at any level) or through various quest perks. Additionally, you can find a bobblehead for each attribute which increases its associated stat by 1 point (which makes raising an attribute to 10 at character creation a waste of points).

Attributes can also be increased temporarily by wearing certain armors and clothing, carrying certain items or using consumables.

For information on increasing specific attributes, please refer to the article for the respective attribute.

Changes from previous Fallout games
Players who are accustomed to the rigid attribute and skill mechanics of the previous games may be happy to know that the new systems in Fallout 3 are much more flexible and allow for more changes during a character's development. For instance, tagging a skill no longer increases the rate of a skill's development, but skills gain their maximum effectiveness (and cap out) at 100. Additionally, while the Gifted trait (along with all traits) has disappeared, primary attributes are simultaneously less important and easier to acquire as your character grows.

Players who played the previous two games should also keep in mind that the SPECIAL system in Fallout 3 is much more forgiving when compared to the first two games: Low ability scores penalize the player less, while high ability scores do not grant as much of a benefit. Where in the first two games lowering a SPECIAL stat to 3 or lower could be a risky move regardless of your character type, characters in Fallout 3 can get away with SPECIAL scores of 1 in particular stats. For example, a character with 1 intelligence will find most character interaction in the first two games impossible, while in the 3rd you simply sacrifice a few Intelligence dependent conversation options and some skill points.