Indeed, "Final Fantasy XII: The Zodiac Age" is a big game. While it has been 11 years since the fantasy role-playing video game was first released, many are still unsure how to unlock and use the Espers.

In "Final Fantasy VI" and "Final Fantasy XII: The Zodiac Age," the Espers are powerful mystical beings that can be summoned to join the player's side. There are 13 available Espers, five of which —Belias, the Gigas; Hashmal, Bringer of Order; Shemhazai, the Whisperer; Famfrit, the Darkening Cloud; and Mateus, the Corrupt — are obtained in the main story.

The other eight — Chaos, Walker of the Wheel; Zalera, the Death Seraph; Zeromus, the Condemner; Ultima, the High Seraph; Exodus, the Judge-Sal; Cúchulainn, the Impure; Adrammelech, the Wroth; and Zodiark, Keeper of Precepts — can be found through the side quests.

In order to obtain them, players must first defeat the mystical beings in their respective dungeons. Espers attack as soon as players arrive in their territory and often, players cannot leave until they defeat them.

Once an Esper has been defeated, it will automatically appear on the License Board and any player can purchase its license. By acquiring every Esper, the player gets the award of "High Summoner." If the player successfully defeats Zodiark, he or she will earn the title of Zodiac Knight.

It is important to note that the Espers require Mist Charges equivalent to their level to summon. For example, the level 1 Espers take one gauge to summon while the level 3 Espers take all three.

However, when an Esper is summoned, the two other party members disappear. Each summon only lasts for one minute and 30 seconds and ends when either the summoner or the Esper dies or the Esper uses its definitive move.

"Final Fantasy XII: The Zodiac Age" is available on PlayStation 2 and PlayStation 4.