The Merged World (also known as the Original World or Third World) is the title given to the third and final world (not counting the Interdimensional Rift) in Final Fantasy V. It is a blend of Bartz's World and Galuf's World, and its geography is that of both worlds fitted together with some noticeable differences; Exdeath's castle is not visible, and the forests in the Gloceana desert are gone, leaving that section a large desert. Locations that were inaccessible previously due to the means of access being on the other world are now open for exploration. At the same time, many areas become inaccessible here due to the Void's power ravaging certain cities: most notably; Castle Tycoon, Walse, Istory, Moogle Village, Lix, and shortly after completing the Pyramid of Moore, the Library of the Ancients.
The landscape is one large continent, with the archipelagos in the south of both worlds connecting (despite there not actually being enough land for this to happen). Many of the continents from the previous worlds fill in large gaps in others, making the entire world more accessible and able to be circled with a chocobo.
The Merged World is how the world originally was before its crystals were separated 1,000 years ago, thus splitting the world into two. This was done to seal the power of the Void in the Interdimensional Rift between the worlds, so none could harness its might for evil. The warlock Exdeath claimed and shattered the crystals, thus pulling the two worlds back into one, and gained access to the power of the Void.
Before their demise the crystals had branded Bartz, Lenna, Faris, and Galuf the Warriors of Light tasked with vanquishing Exdeath and protecting the crystals. Though they failed to stop Exdeath from shattering the crystals, and Galuf was killed and his mantle taken by his granddaughter Krile, the Light Warriors continue on their quest to destroy Exdeath once and for all.
The party infiltrates Castle Exdeath in Galuf's World and encounter Gilgamesh, but his poor choice of weapon is no threat, and Exdeath banishes him to the Interdimensional Rift for his failure. Exdeath battles the party at the top of the castle, and though he appears defeated, he shatters the remaining crystals.
The Light Warriors black out and awake near Castle Tycoon, which throws a celebration for the return of the princesses Lenna and Sarisa (Faris). Bartz and Krile slip out to discover why they returned to the first world, and are soon joined by Faris, who grew tired of being royal. They learn from the great sage Ghido the two worlds have been merged into one. Long ago, the world was split to seal the power of the Void, a destructive power of unknown origin, lest it be used for evil. Now that the world has been restored to its original state the power of the Void has been released to be used by Exdeath.
The Light Warriors must obtain the Sealed Weapons, a set of twelve legendary weapons from a thousand years ago, to survive the Interdimensional Rift, an otherworldly dimension existing in the rift between worlds, and destroy Exdeath. Exdeath emerges from a splinter in Krile's hand and knocks them out, although Ghido fights him to a standstill. Exdeath uses the Void to destroy Castle Tycoon and Lenna with it.
After obtaining the first seal from the Pyramid of Moore to unlock the legendary weapons, the party reunites with Lenna, who was saved from the Void by Hiryu, her wind drake. Hiryu sacrifices himself to help drive the demon Melusine from Lenna's body so the other Light Warriors can defeat her. Exdeath strikes again with the Void, seemingly to taunt the party as well as removing Ghido. The places Exdeath attacks are Walse, Istory, Moogle Village, and Lix. Devastated and infuriated at the destruction of his hometown, an enraged Bartz almost destroys their airship by pushing it to unreasonable speeds before the others calm him down. They reunite with the scholars Cid and Mid after traversing Fork Tower to obtain the Flare and Holy spells, and the pair gives the airship an undersea function.
The Light Warriors explore the Merged World to unlock the legendary weapons using the seals from the Island Shrine, Great Sea Trench, and Istory Falls, defeating the Demons of the Rift Exdeath sent to stop them. They find Faris's sea dragon Syldra as a summon spirit in the Pirates' Hideout and Hiryu as the summon Phoenix at the top of Phoenix Tower.
Now fully prepared, the Light Warriors fly the airship into the Interdimensional Rift that has opened over Tycoon. They fight through the hodgepodge of environments seemingly put together from the places the Void consumed until they reach the final floors, a world of crystalline darkness. Exdeath reveals his true form: the Moore tree. The Great Forest of Moore in Galuf's World had once been used to seal evil spirits, until the day the spirits sealed in a tree became a sentient, malicious being. He tries to destroy the Light Warriors with the Void, but the spirits of the Dawn Warriors—Galuf, Xezat, Dorgann, Kelger—as well as King Tycoon, save them, allowing the party to confront Exdeath in battle. Halfway through the fight he is consumed by the Void and becomes Neo Exdeath, an entity—the manifestation of the evil spirits trapped within the Moore tree that was Exdeath—that seeks to turn all of creation to nothingness. At great length, they defeat it.
For a short time, the Void lingers. The essences of the elements carried by the party—Hope, Courage, Devotion, and Passion—imbue the crystal shards they carry, and the crystals are reborn in the places that held the weapon seals. It is told the Void existed before the world, and that the crystals that sustain the planet were born in the Void and thus created the world. From this it can be drawn that the Void is the original state of the universe from which all life was formed. King Tycoon and the Dawn Warriors thank the party for saving the world and Krile's wind drake appears to take them back.
A year later, Krile writes to Mid and tells of what the Light Warriors have been up to. Bartz has resumed wandering. Lenna and Faris returned to Tycoon, although Faris cast aside the life of royalty to rejoin her pirate crew. Krile herself returned to Bal. She visits the Guardian Tree on the anniversary of Galuf's death, feeling sad and lonely, but the others join her and remind her she isn't alone. Should any of the party have fallen in the final battle, they are revived at the Guardian Tree. Together, they vow to continue protecting the crystals.
- Pyramid of Moore - A great pyramid that, in Bartz's World, stood in the center of the Desert of Shifting Sands. In the Merged World it is now located where the Forest of Moore was.
- Fork Tower - A double tower that appears on top of the Catapult. The spells Flare and Holy rest atop one side of the tower, with Meteor on the other. Previously inaccessible in Galuf's World due to being surrounded by mountains. Disappears upon completion, opening up the Catapult.
- Island Shrine - A tiny island accessed via Big Bridge. Previously inaccessible in Bartz's World due to being surrounded by mountains.
- Phantom Village - A village trapped in time, caught in the Interdimensional Rift 1,000 years ago. Previously inaccessible to the laws of physics.
- Great Sea Trench - An underwater cave accessed by submarine. Previously inaccessible in Galuf's World/Bartz's world due to the submarine not being present in the latter and potentially not existing the in the former.
- Istory Falls - A great cave complex beneath the waterfalls. Previously inaccessible in Bartz's World.
- Phoenix Tower - A 30-floor tower where the Phoenix summon rests. Previously inaccessible in Galuf's World due to being surrounded by mountains.
- Unknown Cave - An underwater cave where a man named Mr. Clio will tell the party their battle stats.
- Interdimensional Rift - a bizarre mixture of dimensions between worlds. Previously inaccessible due to the laws of physics and having been sealed prior to the merger. Replaces Castle Tycoon on the map.
- Sealed Temple- An optional dungeon exclusive to the Android, iOS and GBA versions.
Notable alterations from the other worlds
- Castle Exdeath is replaced by a normal forest and river directly southwest of Castle Tycoon.
- The Sealed Castle Kuzar now stands in place of the small forest where Exdeath was sealed, with Regole now southwest of Lix.
- The Big Bridge now unlocks the Island Shrine.
- Most of the sea west of Walse and Carwen is replaced by the Gloceana Desert, albeit without the forests. This also unlocks the Phoenix Tower in the southwestern portion of the desert.
- Most of the Great Forest of Moore is replaced with the Great Pyramid and its surrounding desert, though the Guardian Tree remains.
- Surgate now sits directly north of the Ancient Library.
- Bal, Quelb and Drakenvale now border the mountain range that stretches from the Desert of Shifting Sands all the way to Jachol.
- The southern archipelagos from both worlds act as one continuous strip of landmass, along with the Fork Tower island and Crescent Island becoming part of that strip.
- The underwater cave that originally led to Catoblepas's forest in the northwestern continent now leads to Istory Falls.
- Tule area
- Surgate Castle / Library of the Ancients area
- Moore area
- Kuza area
- Crescent / Fork Tower area
- Island Shrine area
- Istory area
- Phoenix Tower area
- Water Scorpion
- Vilia (southwest corner of the world map)
- Gel Fish
- Sea Devil
- Stingray (Walse region)
The overworld theme for the Merged World is called "A New World". The track also appears on A New World: intimate music from Final Fantasy as a live recording from at the London premiere of the concert of the same name on February 15, 2014, conducted by Arnie Roth.
The Merged World appears as the Field Music Sequence for "A New World".