Balthier's main playable appearances are in Final Fantasy XII and its sequel, Final Fantasy XII: Revenant Wings. He is the weakest male party member in Final Fantasy XII and emphasizes ranged attacks in Revenant Wings. In Final Fantasy XII, Balthier, alongside Fran, is the first permanent party member to join Vaan. In Revenant Wings, he joins the party fairly late.
Balthier's HP growth and Strength are good though lower than Vaan's and Basch's. His Speed is the highest of the six main playable characters. His MP and Magick Power growth are low. Balthier is well-suited for close combat. Conversely, his low magick stats mean he is ill-suited for healing or using black magick. When he joins, his starting level is determined by Vaan's current level. Balthier, alongside Vaan and Basch, have the best combo speed with the high-combo weapons, and thus are good candidates for job combinations that exploit this in The Zodiac Age version.
Even though Balthier's default weapon is a gun and he has gun licenses already learned, Balthier has the slowest action time, together with Penelo, when using a gun—all the other characters' action time with a gun is faster. Thus, it is best to equip him with other weapons that make good use of his strength and speed stat such as daggers, ninja swords, bows, greatswords, and spears. After winning a boss battle the currently alive members of the active party perform a victory pose depending on what weapon they are equipped with.
Balthier equips guns. His armor equips—sleeveless tops—all favor Defense over Magick Defense. His accessories are rings. He takes on the role of a ranged fighter. His Quickening, Element of Treachery, deals heavy damage to one foe, and is learned after defeating the Esper Shemhazai.
↑http://youtu.be/17ME_DLnk3Q?t=2m30s - Fran's initial LP is Vaan's Total minus 120. As Fran's initial LP is 131, Vaan's Total is 251. Fran's initial LP (131) plus LP from starting licenses (155) equals 286. [(251+286)/2]-135=133.5 or 133 without the decimal, which is Balthier's initial LP.
↑The Piggyback Official Strategy Guide erroneously indicates the formula as being "(Half of Vaan's LP) + (Fran's LP - 135)". Final Fantasy XII Piggyback Official Strategy Guide. p63.