SPECIAL

SPECIAL is the ruleset that powers Fallout online, The name "SPECIAL" is an acronym standing for the primary statistics in the system:

• S is for Strength which modifies Hit Points, melee damage, and Carry Weight.
• P is for Perception which modifies Sight, Sequence, and ranged combat distance modifiers.
• E is for Endurance which modifies Hit Points, Poison and Rad Resistance, Healing Rate and additional Hit Points per level.
• C is for Charisma which modifies Party Points, NPC reactions, and more.
• I is for Intelligence which modifies additional Skill points per level, dialogue options, and many Skills.
• A is for Agility which modifies Action Points, Armor Class, and some Skills.
• L is for Luck which modifies critical Bypass, weapon failures, and certain unseen factors as you play.

These factors are also involved with the availability of certain perks and might modify certain mechanics of the game not explicitly listed here. It is a good idea to keep an eye on the Changelogs.