Each character has six ability scores (Strength, Dexterity, Constitution, Intelligence, Wisdom, and Charisma) that represent his character's most basic attributes. They are his raw talent and prowess.
While a character rarely rolls a check using just an ability score, these scores, and the modifiers they create, affect nearly every aspect of a character's skills and abilities. Each ability score generally ranges from 3 to 18, although racial bonuses and penalties can alter this. An average ability score is 10.
To generate your character's Ability Scores, roll 4d6. Discard the lowest result and add the remaining results together. Record this total and repeat the process until seven numbers between 3 and 18 are generated. Discard the lowest result and assign the remaining six numbers to your Ability Scores as you see fit.