In Dungeons & Dragons, each character has six main abilities: Strength, Dexterity, Constitution, Intelligence, Wisdom, and Charisma. These abilities represent a character's basic attributes and are used to determine a wide range of skills, actions, and characteristics.

There are several methods to determine ability scores:

Rolling: The traditional method involves rolling four six-sided dice (4d6) and recording the total of the highest three dice. This is done six times, once for each ability. This method can result in characters with a wide range of abilities, from very strong to very weak.

Point Buy: The point buy system gives players a pool of points (usually 27) that they can distribute among their abilities as they see fit. Each ability starts at 8, and it costs points to increase an ability score. The cost increases as the score goes above 13. This method allows for more balanced characters and gives players more control over their character's abilities.

Standard Array: The standard array method provides a fixed set of scores (15, 14, 13, 12, 10, 8) that players can assign to their abilities as they wish. This method is quick, and easy, and ensures a fair distribution of ability scores.

After determining the raw scores, players then apply any racial bonuses or penalties. For example, an Elf character might get a +2 bonus to Dexterity, while a Dwarf might get a +2 bonus to Constitution.

Finally, each ability score is translated into a modifier according to a standard scale. The modifier is the number you add to or subtract from a die roll when your character tries to do something related to that ability. For example, if you have a Strength score of 16, your Strength modifier is +3. This modifier is used for things like attack rolls, damage rolls, and skill checks.