Intelligence (INT) is a crucial stat for any job class that focuses on offensive spell casting as it serves to determine how effective all Black Magic based Enfeebling Magic, Elemental Magic and Enhancing Magic spells will be. In addition, Ninjutsu and Magical (as opposed to Physical) Blue Magic spells receive boosts from Intelligence as well.
Magic Accuracy is also affected by Intelligence in that higher INT will result in a higher Magic Accuracy score and lead to less resists when casting. Interestingly, this stat will also increase the damage and proc rate from Elemental arrows (Water Arrow, Earth Arrow, Wind Arrow).
When it comes to INT, the Tarutaru have it made. While all races can become incredibly effective Black Mages, many people choose Taru because of their advantage in the Intelligence department and their naturally large MP pools. The breakdown of a level 1 Black Mage by race is as follows:
As with all basic stats, it is possible to permanently increase one's INT by the use of Merit Points by up to five points. Additionally, gear that focuses on INT and choosing a good INT food will help even non-merited characters achieve a high Intelligence score.