The Super Nintendo Entertainment System/PlayStation/Game Boy Advance versions of Final Fantasy IV have a lot of dummied content. This includes enemies, weapons, and dialogue, among other things. Some of this content was later restored for some of the ports and remakes.
There is an unused command within the game's data, but it's only named in the original Japanese version, Airship (ひくうてい, Hikūtei?). The command is configured to target all enemies, but crashes the game when used. Given the name and positioning in the command list, it appears it was intended for Cid. The Game Boy Advance version introduces another unused command called Dbl Mtr (Double Meteor). This was likely intended to replace the Twincast command when the Twin Stars were equipped on both Palom and Porom.
In the Super Nintendo version, the Bardsong command is dimmed out only when Edward is not equipped with a harp. In the game's data, the group of weapons ranging from 44 to 4C enables the Bardsong command. These include the two original harps, Dream Harp and Lamia Harp, but also include the two-handed Ragnarok, the Poison Axe, the Rune Axe, the Mythril Hammer, the Gaia Hammer, the Wooden Hammer, and the Avenger. More harps might have been planned and later changed into the other weapons later during development.
The four summon items have a missing item description not viewable in-game, even though the text exists in the game's data. There was supposed to be a message displayed when one of Rydia's summon monster items is highlighted. The SNES description is "Caller's Magic Orb".
One piece of unused dialogue exists: "You are entering into my realm, the Zemus-Zone. No one can ever escape from my minions! Perish in the Darkness before you reach me". This is most likely a speech given by Zemus, taunting the party telepathically. This was intended to be displayed upon entering the Lunar Subterrane before the player fights Zemus's minions that guards the powerful equipment. The "Zemus-Zone" is also an unused location name.
During the battle against Yang in Baron, he was originally intended to specifically target Cecil with physical attacks every turn, provoking responses from Cecil. This is never executed because the developers mistakenly had Yang target Dark Knight Cecil instead of Paladin Cecil. Cecil's responses to Yang's attack are as follow: "Come on, Yang!" and "...... It's me!" Yang's script in the 3D remake version was fixed, and Cecil will say his two lines, but Yang will Kick in-between them instead of simply attacking.
Rydia has a line not spoken that was going to be said somewhere in the Feymarch. this lines is found between her other lines used there. The line is as follow; "Rydia:I lived here! Let's see if we can find something we can use."
Another line, "I don't like Baigan" is found with Baron Castle's text strings. No one there outright states their dislike for him.
"Character" battles do not make use of normal physical attacks, but making it so reveals an interesting thing. If a character attacks physically, they'll use Cecil's Deathbringer, rather than the correct weapon as would be expected. If their AI script is altered to make use of physical attacks, said character will use Deathbringer. This might have been intended specifically for the Dark Knight battle atop of Mount Ordeals, which mirrors Cecil who would have been equip with his more powerful weapon at the time, Deathbringer, but decided to go with Darkness instead.
A few enemy formations that involve regular monsters went unused, and can never be encountered normally. Such formations include a group of three Goblins and three Domovois; they are arranged the same like the three Domovoi and three Gatlinghog formation. There is also a Centaurion appearing with two Eukaryotes. There are quite a few unused formations in the Tower of Zot, Sealed Cave, and inside the Giant of Babil locations.
There is at least one unused monster; the Imp, who even has an attack script. Found within the data, this monster is a dark purple and red palette swap of the Gremlin and Mini Satana monsters. It is not to be confused with the translation used for the Goblin monster in the early English versions, or the 3D version's name of Mini Satana. The Imp's name was changed to Dummy in the English SNES release and the Easy Type version in Japan. Based on its stats, it was probably intended to be encountered on the surface of the moon or in one of the deleted floors of the Tower of Bab-il. In the Final Fantasy IV: The Complete Collection release, the Imp was cut and replaced with a distorted sprite using the Wii version graphics, just like numerous other enemies that were cut from the list.
Enemies can use elemental physical attacks, but none of the monsters actually have an element set up for their physical attack. Physical weaknesses, unlike magical, override resistances, and a character with a piece of fire resistant armor and a piece of ice resistant armor equipped will take double damage from an enemy attacking physically with either of those elements. Much of the late game equipment provides both fire and ice resistance, which would make it a hindrance when facing enemies that attack physically with either element.
There is a two-handed Ragnarok in the item list within the game's data, found between the Lamia Harp and the Poison Axe. It does not have a sword icon, but is named None (Spare in the original Japanese version). It cannot be equipped by anyone. If the data is modified to allow it to be equipped, the player will find that it is a two-handed weapon. If force-equipped to a character, its weapon graphic is the same as the Ragnarok's, and its attack and sound effect are also the same. It has the same Holy attribute with an attack power of 200, the same attack power as the single-handed Ragnarok. This sword is not obtainable in any version of the game, but exists in all versions of Final Fantasy IV, including Final Fantasy IV: The After Years.
In the SNES version, the Assassin Dagger was dummied out. This dagger has an attack power of 29, accuracy of 55%, +5 Strength, +5 Agility, +5 Stamina, -10 Intelligence, and -10 Spirit. The weapon can also inflict instant death. It can still be found within the data of newer Final Fantasy IV versions. This is not the same Assassin's Dagger introduced in the Finest Fantasy for Advance version; the latter is substantially more powerful, with its stats increased for its appearance at the end of the game.
Cid's hammers use a wrench icon, but there is also a hammer icon that goes unused. The light blue color is the background.
Instead of setting its elements/statuses directly on weapons, armor, items, magic, and enemy abilities, the game uses an index which points to a table of element and status combinations. Some of these combinations are not actually used.
- Fire Immunity: Grant immunity to fire.
- Ice Immunity: Grants immunity to ice.
Immunity is only used on two armor pieces: the Glass Mask and Adamant Armor. The immunity bit is bugged. When placed on an armor piece, the character wearing it becomes immune to all elements that piece protects against and gains 99% evasion. It will also make the wearer of said armor piece weak against any elements they are supposedly immune to and makes them take quadruple the damage from any elements they were already weak against when the armor piece is removed from them.
- Pig/Mini/Toad: The three transformation statuses would of likely been used on a piece of armor.
- Fire/Ice/Thunder/Dark/Holy: The five elementals would of also been used on a piece of armor.
- Dark/Blind: This comes before the Dark/Death set used by the Deathbringer, implying it was intended for a Dark Sword before acquiring the Deathbringer at Fabul. No weapon outside of Cecil's Dark Sword uses the Dark element.
- Ice/Paralyze: A property of whip weapons wielded by Rydia, this directly follows the index used by the Flame Whip. This was used for the Ice Whip in the sequel to Final Fantasy IV.
There are three Add Status effects, later two, that do not make an appearance; the Mini, Pig, and Toad. However, there is text for the three of them for when a weapon was successful in inflicting these statuses on the enemy. A player can see these if these statuses are hacked onto a weapon. The Pig status was used in the Game Boy Advance version, the Hog Call weapon.
Unlike the other characters that leave the party permanently, Cid's stats are saved up until the time Fusoya departs for the Red Moon, at which point they are overwritten. This means that he may have been intended to rejoin the party at some point during development. Cid also has a dummied out command called Airship.
In the North American SNES version, nearly all the items that could invoke magic spells were removed from the game in Easy Type, with the exceptions being the Red Fang (FireBomb) and Blue Fang (Lit-Bolt), shown in the opening battles.
The removed items Muddy Water and Raggedy Doll from the Game Boy Advance hint that one of the Lunar Ruins floors was originally intended to be more complex. These items are "bad" counterparts to the Clear Water and Doll that must be obtained in the final version. Text strings for these two items would've been used when the Muddy Water and Raggedy Doll were used in place of the correct item. The first text: "The lifeless tree looks deader than before..." while the second "The boy seems to be frightened by the man."
Additionally, all of the items intended to cure a single status ailment have been removed, replaced by the Remedy (Heal). The rare Cockatrice summon spell and the Alert item would both be referred to as Dummy in the item menus, and all dummied out items retain their original effects. The only way to access these items is with a Game Genie, specifically the code that rotates the item ID of the first item slot in the inventory whenever a character is healed.
In the DS version, there are three tails that were dummied out: Takkei Tail, Omega Tail, and Zemus Tail.
An unused battle background exist within the game's data of Final Fantasy IV Advance, which was intended to be used for battles taking place in the town's exterior. This background would have fit in for Rosa's trial that takes place inside the Lunar Ruins, but it uses the castle interior background instead despite taking place outside. The PSP version has a town exterior which is vastly different than the GBA version and it is used during Rosa's trial.
The Debug Room is only accessible on the US or Australian version of Final Fantasy IV Advance. The Debug Room is a small room and the player will need a Gameshark device to access it.
The Tower of Babil has a large crystal room. Beyond the altars in the back of this room is a doorway. The door leads to a hallway behind the crystal room, which can be seen normally, but there's no way to reach it without cheating. There's nothing here, however; while the door in the upper left corner opens, it not only leads nowhere, but it also causes minor graphical glitches. There's no way to get back into the crystal room once the player is here, meaning they are trapped. This area might have been explorable at some point during development.
There is one empty and unused magic menu found within the game's data which, based on the internal character order, was intended for Kain. He also has an unused two-frame animated sprite for casting spells. The Final Fantasy IV Settei Shiryou Shuu shows a screenshot of Kain with a White Magic command. In the PSP remake, all playable characters have a magic stance, including those that do not have a magic command.
Certain weapons can cast magic when selecting to equip a weapon from the item menu during battle. These require three pieces of data to function properly: a spell effect, a spell's visual to use, and a spell power value. Some of this data is not written in the code, making their spells non-functional. The Power Staff apparently was supposed to cast the Berserk spell, and the player can hear its sound effect when used on a reflected party member. The other is the Wooden Hammer, which was meant to cast Thundara, and its sound effect can be heard the same way. It has no spell power associated with it. Fire Whip has a spell power of 4, but it has no spell effect.
When Rydia rejoins the party as an adult in the Dwarven Castle after beating Golbez, she automatically learns Fira, Blizzara, Thundara, along with Cura. At this point, she no longer has a White Magic command and thus cannot use her White Magic spells, meaning Cura can never be cast. If the White Magic command is hacked into adult Rydia's command menu, she'll have access to Cura along with the other three White Magic spells.
Anna is seen in battle form at one point, but only the first frame of her sprite is shown. But she has other unused extra frames that are not loaded in the battle in Kaipo in which she appears. They appear in the automated battle just prior to the final battle, in which Fusoya and Golbez fight Zemus. This is because Golbez and Anna share the same sprite sheet, therefore, the extra sprites are called when Golbez is used.
There's a two frame flag animation found alongside the vehicles used on the overworld. This flag was likely intended for Kain's airship when he approaches the Enterprise after lifting off at Baron Castle, given that the dialogue there mentions a white flag for surrender. When using the Enterprise's palette, it makes it white.
On the PlayStation loading screens, there are a few sprites that appears on the leading screens. These are paladin Cecil, the dancing girl, a yellow chocobo, a toad, and mini. These sprites have several unused sprites that can be found in the TIM used on the load screens. Cecil has a running, jumping, cover, and falling over sprites. He is only seen using the standing animations on the screen. The dancing girl isn't used at all. A yellow chocobo appears on the loading screen, unseen is the walking, flying animation frames. The later is probably because yellow chocobos cannot fly. The Toad has several unused frames much like the others, and they seem to match those used by the dancing girl, implying they may have been intended to be used together. The Mini doesn't appear at all, and much like the toad, his frames match those used by the dancing girl.