Casters specialize in dealing magic damage primarily at range, using a mix of instant and casted spells to maximize damage and uptime while managing job movement restrictions amid fight mechanics. The role is highly flexible due to vastly different job mechanics and playstyles, and features a large range between pure DPS and various levels of utility.
Black Mage is a caster specializing in high, steady personal damage in place of providing party buffs. The job maintains a cyclical flow of expending MP via long, powerful casts in Astral Fire then swapping to refresh MP in Umbral Ice. While the rotation itself is somewhat simple, utilizing its movement tools and the flexibility built into its rotation to their fullest is key to maintaining uptime and maximizing damage as a Black Mage.
Red Mage is a magical DPS with powerful melee combos that allow it to burst DPS during party buffs, and oGCDs that allow it to deal consistent damage through the duration of a fight. Alternate between casting spells to build your Black and White mana, and spend that mana to use melee abilities that chain into powerful finishers. Red Mage also has Dualcast, which makes every other spell used an instant cast, allowing experienced Red Mages to maximize their casting uptime throughout a fight.
Summoner is a caster DPS that juggles pet abilities, damage-over-time effects, an Aetherflow gauge, and more. The rotation features a powerful burst window, able to summon the mighty Demi-Bahamut and Demi-Phoenix, and also deals a large amount of area-of-effect damage. With powerful and consistent bursts, Summoner is able to contribute a lot of damage into party buffs. It also brings an impressive suite of utility to a raid progression setting, with its own party damage buff, a powerful on-demand shield on a short cooldown, and its very own resurrection ability.