Final Fantasy III is the first game in the series to feature Summons: Beasts that the party can call upon to aid them in battle. Summons would take on many forms in the FF series, having a god-like presence, the flashiest of moves and mechanics that can make them feel like fellow (if temporary) party members.
Despite being comparatively simple, FF3's system is a bit more complex than some of those that came after. Each Summon has three different skills to them: A White Magic effect, a Black Magic effect and a High summon attack. Despite the label, the terms "White Magic" and "Black Magic" are a bit misleading: The "White" Effect is usually a form of buff to the party or status to the enemies while the Black Effect is usually direct damage. The catch is that which effect you get is decided entirely at random. The White and Black Magic attacks can be used by Evokers, while the High attack is used by Summoners; Whether Sages get all three effects or just the Evoker's effects depends on whether you're playing the 2D version or not.
The Famicom version varies the summon's palette depending on what effect they'll do. This was not carried over to the 3D or Pixel Remaster versions.
Escape is the Level 1 summon and something of a joke summon. Escape summons a Chocobo rather than any of the giant beasts and one of the two Evoker options equates to doing nothing. Its abilities are:
This ability allows the party to flee from battle. It's useful for escaping a fight and not dealing with III's punishing run away mechanics, but obviously not very good for fights you actually want to have or can't run away from.
A joke effect: The Chocobo attempts to kick the opponent. As the question mark indicates, the effect will always fail.
Chocobo Kick except it doesn't fail this time. Unfortunately, the attack power is pretty low for where you get it, so the primary saving grace becomes its surplus of casts.
Icen is the level 2 summon. It is Shiva's summon and the first to have a Status White Magic effect. As a general rule, these are useful in the Famicom version as they have a guarenteed hit rate, but are much more of a gamble in the remake due to the rates getting nerfed. Keep in mind that bosses are generally immune or heavily resistant to "skip turn" statuses or Instant-Kill moves.
For this ability, Shiva puts the enemies to sleep. This can be good for buying time for the party to heal or buff.
Shiva attacks the enemy with an ice attack.
Shiva hits all enemies with an ice attack.
Spark is Ramuh's spell and occupies spell slot #3. Ramuh kind of gets the short end of the stick, as he doesn't have anything particularly notable as far as summons go. He's basically "Shiva but lightning".
Ramuh paralyzes the enemies. Much like Shiva, this can be good to get a grace period or to lower their numbers.
Heatra represents Ifrit and is a 4th level spell. Ifrit is one of the more useful Evoker summons because both of his effects are useful and hard to waste.
Ifrit heals the entire party. The healing factor is rather effective, making it a decent move.
Ifrit attacks one of the enemies with a fire attack.
Spell tier #5 belongs to Titan. Titan is unique in that every effect that he has is some form of attack. This means that if you want guarenteed damage and the enemy doesn't resist/isn't immune to Eath, Titan is your man.
Catastro is the first of the "Boss" summons, which require the Warriors of Light to either fight bosses in order to receive them or purchase them in Eureka at the end of the game. In the case of Catastro, Odin must be defeated in order to get the summon ability.
Leviath is the second "Boss" spell, meaning that the Warriors of Light must defeat it to gain the spell and the ability to call upon the power of Leviathan. Compared to the other summons, Leviathan's elemental coverage is weird, covering both wind and water.
One of the earliest instances of the recurring spell, Leviathan attempts to turn enemies to stone. Has an absurdly low hit rate.
Leviathan attacks the target with a single target wind spell.
Leviathan attacks the enemy party with a deluge of water.
Bahamur is the final summon spell and occupies the eighth spell slot. As the name implies, it is based on Bahamut and requires the player best the Dragonking in battle before they can use it. Much like Ifrit, Bahamut's effects are useful enough that it's hard to waste a cast, which is good as Bahamur occupies the tier with the least casts.
The party encounters Bahamut early on in the game through an encounter that is nigh-unwinnable. The player is intended to flee from the fight. Only later can they truly challenge the Dragonking and win the summon.
Bahamut previously appeared in the original Final Fantasy: There, he provided a test for the Warriors of Light and upgraded them to their advanced jobs if they were to succeed. As FF3 introduces summons, this marks the beginning of Bahamut's status as a summon beast, and one of the mightiest at that.
Bahamut grants the party an aura, increasing their attack power.
The first appearance of Bahamut's signature move: Bahamut blasts the opposing team with with a powerful laser.