Charisma measures a character's force of personality, persuasiveness, ability to lead, and physical attractiveness. It represents actual personal strength, not merely how one is perceived by others in a social setting. Charisma is most important for paladins, sorcerers, and bards. It is also important for clerics, as it affects their ability to turn undead. All characters benefit from having a high charisma when speaking with others in the world. Charisma affects an NPC's initial reaction to the player and it modifies the player's persuasion skill checks.
Note: Charisma influences bard/sorcerer spells, not intelligence.
The base charisma score is used to determine the highest level spell a bard or sorcerer can learn. This maximum spell level is the score minus ten.
The charisma modifier is added to the DC of spells cast by a bard or sorcerer. In addition, bards and sorcerers gain bonus spell slots based on this modifier; for details see ability modifier. Furthermore, the charisma modifier is added to the animal empathy, bluff, intimidate, perform, persuade, taunt, and use magic device skills.