The Grand Saga
Ability scores are generated using an initial ability score of 10 in each stat, and adding points on a 1-for-1 basis to each ability score, to a maximum of 30 points added. This is your base ability score. Your base ability score can never go above 18. After you have distributed your 30 points, you then add racial modifiers.
The maximum permanent ability score is 24. Temporary bonuses, such as those provided by magic items and spells, can bring your ability score to a maximum of 30. Size modifiers are not considered when comparing your ability score to these maximums.