The following guide details the extra scenes in FF9: The Zodiac Age.

LEGEND DESCRIPTION
None No special conditions required.
[Character] is in current Party Extra scene checking if a specified character is in the current player's party at the time.
Party average Level Base current Party's Level recommended for that scene's battles.
Defeated [Enemy] Extra scene checking if specified [Enemy] has been defeated.
Speak Speak with specified character, initiating extra scene.
Initiate Interact with specified object and begin extra scene.
DISC 1 EXTRA SCENE LOCATION REQUIREMENTS CONDITIONS/BENEFITS
Evil Forest None Talk to Vivi. Obtain Loot: 'Dark Stone'.
Marshland Derrick (Dagger) in the current Party Speak with Asura first; defeat Asura. Obtain equipment. Speak with Eidolon King; defeat Leviathan. Obtain equipment.
DISC 2 EXTRA SCENE LOCATION REQUIREMENTS CONDITIONS/BENEFITS
Esper's Cave/Jonah None Defeat Behemoth King and Apparition of IV and XII. Reward: 2 Secret Shops
Esper's Cave/Amdusias Zach (Zidane) in the current Party Defeat Krarklilith. 1st required condition to unlock 'Daughter Diaries'.
Marshland Derrick (Dagger) in the current Party. Party average Level: 35+ Defeat Asura first. Defeat Leviathan second. Reward: Equipment.
Marshland Never entered Fossil Roo Speak with Luke (Cinna) before entering Fossil Roo for the first time. Benefit: Recruit Cinna in your Party.
DISC 3 EXTRA SCENE LOCATION REQUIREMENTS CONDITIONS/BENEFITS
Esper's Cave/Jonah Party average Level: 50+ Defeat Behemoth King and Apparition of IV and XII. Reward: 2 secret shops.
Marshland Derrick (Dagger) in the current Party. Party average Level: 42+ Defeat Asura, Defeat Leviathan. Reward: Equipment.
South Gate/Treno Arch Disc 3 only. Party average Level: 52+ Defeat Barbara-Kerbria. Required for Montblanc to appear at Mognet Central. 2nd requirement to unlock 'Daughter Diaries'.
Abandoned Site/Mognet Central Defeated Barbara-Kerbria. Defeated Barbara-Kerbria required to keep Montblanc at this location through Disc 4. Montblanc cannot be found elsewhere. Benefits: Secret Shop.
Esper's Cave/Amdusias Zach (Zidane) in the current Party. Party average Level: 65+ Defeat Krarklilith. 1st required condition to unlock 'Daughter Diaries'.
Daguerreo/Entrance 'Daughter Diaries'~Speak with Steiner. Krarklilith and Barbara-Kerbria defeated. Obtain: 'Daughter Diaries' key items.
Daguerreo/Entrance~Asura Party average Level: 68+ Defeat 3 consecutive battles: Soul of Rydia/Magick Vice. Esper: Cúchulainn/Magick Vice/Echidna. Magick Vice/Pylraster/Diabolos. Reward: Equipment.
Lindblum Castle/Airship Dock None Near the horseman statue, near Nyx Ulric (Blank), speak with the 2000 spirits of Gaia: (Zidane/Dagger/Steiner/Vivi/Freya/Eiko/Quina/Amarant). Conditions required.
Lindblum Castle/Airship Dock Defeated Esper: Zodiark. Defeat Zodiark to unlock the secret shop and option to battle the Judges: Zidane, Eiko and Amarant. Reward for battle: Weapon Equipment.
Daguerreo/Entrance/Amdusias None Interact with the Amdusias in the Entrance's far distance to be led to Fossil Roo/Henne Mines/Special Charter Shaft.
Henne Mines/Special Charter Shaft Party average Level: 70+ Continue through the mines and reach Henne Mines/Special Charter Dig. Abysteel battles are recommended for a Party with an average Level of 70 and up, and abilities learned above 70%.
Henne Mines/Special Charter Dig Defeat Zodiark. Party average Level: 85+ Defeat Zodiark with a party average level of 85 and up and abilities learned above 75%. Reward: Weapon Equipment, Recruit Nyx Ulric (Blank) permanently in the current party. *Note: If Zodiark is defeated in the Henne Mines before reaching Ipsen's Castle for the first time, Nyx (Blank) will not be an available party member at all, and other scenes required for Nyx (Blank) will be unavailable.
Ipsen's Castle/Small Room None Speak with the Soul of Rydia at the Feymarch (Ruined). Benefit: Recruit Rydia (Marcus) in the current party.
Ipsen's Castle/Sword Room None Defeat Golbez. Required to unlock scene in Esper's Cave/Outcove.
Esper's Cave/Outcove/Jonah Defeated Golbez. Defeat Hell Wyrm, Yiazmat, Elder Wyrm and Mistomat. Reward: Equipment. Option to reset trials: Asura battles in Daguerreo, Golbez battle and Samuel battle becomes available.
Mount Gulug/Extraction Circle After obtaining Hilda Garde 3 airship. First entrance to Tomb of Kraark/Destiny's March.
Esper's Cave/Magick Field Defeated Zodiark. Nyx Ulric (Blank) in current Party. Party average Level varies between 65 - 85+. With Nyx (Blank) in the party at all times, interact with the steaming field at the bottom of the rope in the Esper's Cave. Choose the desired skill to master. Option to enter Tomb of Kraark/Destiny's March becomes available.
Tomb of Kraark/Destiny's March Nyx Ulric (Blank) in the party. Party average Level: 90+ Defeated Zodiark. Nyx Ulric in the current party. Larva Eater battles require a party's average level around 90 and up, and abilities learned above 90%. Defeat 5 consecutive battles: Esper: Hashmal, Esper: Chaos, Esper: Exodus, Eidolon: Sacrosanct and Master Kraark. Reward: Equipment, weapon equipment.
Pandemonium/Maze Defeat Nox Dragon. Party average Level: 82+ Defeat the Nox Dragon with a party average level of 82 and up, and party's learned abilities above 80%.
DISC 4 EXTRA SCENE LOCATION REQUIREMENTS CONDITIONS/BENEFITS
Esper's Cave/Jonah Party average Level: 50+ Defeat Behemoth King and Apparition of IV and XII. Reward: 2 secret shops.
Marshland Derrick (Dagger) in the current Party. Party average Level: 42+ Defeat Asura, Defeat Leviathan. Reward: Equipment.
Abandoned Site/Mognet Central Defeated Barbara-Kerbria. Defeated Barbara-Kerbria during Disc 3. Benefits: Secret Shop.
Esper's Cave/Amdusias Zach (Zidane) in the current Party. Party average Level: 65+ Defeat Krarklilith. 1st required condition to unlock 'Daughter Diaries'.
Daguerreo/Entrance 'Daughter Diaries'~Speak with Steiner. Krarklilith and Barbara-Kerbria defeated. Obtain: 'Daughter Diaries' key items.
Daguerreo/Entrance~Asura Party average Level: 68+ Defeat 3 consecutive battles: Soul of Rydia/Magick Vice. Esper: Cúchulainn/Magick Vice/Echidna. Magick Vice/Pylraster/Diabolos. Reward: Equipment.
Lindblum Castle/Airship Dock None Near the horseman statue, near Nyx Ulric (Blank), speak with the 2000 spirits of Gaia: (Zidane/Dagger/Steiner/Vivi/Freya/Eiko/Quina/Amarant). Conditions required.
Lindblum Castle/Airship Dock Defeated Esper: Zodiark. Defeat Zodiark to unlock the secret shop and option to battle the Judges: Zidane, Eiko and Amarant. Reward for battle: Weapon Equipment.
Daguerreo/Entrance/Amdusias None Interact with the Amdusias in the Entrance's far distance to be led to Fossil Roo/Henne Mines/Special Charter Shaft.
Henne Mines/Special Charter Shaft Party average Level: 70+ Continue through the mines and reach Henne Mines/Special Charter Dig. Abysteel battles are recommended for a Party with an average Level of 70 and up, and abilities learned above 70%.
Henne Mines/Special Charter Dig Defeat Zodiark. Party average Level: 85+ Defeat Zodiark with a party average level of 85 and up and abilities learned above 75%. Reward: Weapon Equipment, Recruit Nyx Ulric (Blank) permanently in the current party. *Note: If Zodiark is defeated in the Henne Mines before reaching Ipsen's Castle for the first time, Nyx (Blank) will not be an available party member at all, and other scenes required for Nyx (Blank) will be unavailable.
Ipsen's Castle/Small Room None Speak with the Soul of Rydia at the Feymarch (Ruined). Benefit: Recruit Rydia (Marcus) in the current party.
Ipsen's Castle/Sword Room None Defeat Golbez. Required to unlock scene in Esper's Cave/Outcove.
Esper's Cave/Outcove/Jonah Defeated Golbez. Defeat Hell Wyrm, Yiazmat, Elder Wyrm and Mistomat. Reward: Equipment. Option to reset trials: Asura battles in Daguerreo, Golbez battle and Samuel battle becomes available.
Esper's Cave/Magick Field Defeated Zodiark. Nyx Ulric (Blank) in current Party. Party average Level varies between 65 - 85+. With Nyx (Blank) in the party at all times, interact with the steaming field at the bottom of the rope in the Esper's Cave. Choose the desired skill to master. Option to enter Tomb of Kraark/Destiny's March becomes available.
Tomb of Kraark/Destiny's March Nyx Ulric (Blank) in the party. Party average Level: 90+ Defeated Zodiark. Nyx Ulric in the current party. Larva Eater battles require a party's average level around 90 and up, and abilities learned above 90%. Defeat 5 consecutive battles: Esper: Hashmal, Esper: Chaos, Esper: Exodus, Eidolon: Sacrosanct and Master Kraark. Reward: Equipment, weapon equipment.
Lindblum Castle/Telescope None Speak with Derrick (Dagger). Accept Hunt for Yiazmat if not already defeated during Disc 3. Obtain: Equipment. Returns Derrick (Dagger) to Invincible Airship.
Ipsen's Castle None Initiate Part 1 of 2 extra scene. Derrick is removed from the party. Go to Esper's Cave.
Esper's Cave Initiated first scene in Ipsen's Castle Part 2 of 2. Speak with 'James' (Amarant). Defeat Esper: Zalera. Continue scene; defeat The Dark God and Improper Maenad. If Rydia (Marcus) is in the party, is allowed to fight along with Derrick (Dagger). Finish scene; obtain equipment. Benefit: Deniece (Eiko) learns a new skill not found from any equipment. Party defaults to characters: Zach (Zidane), Derrick (Dagger), Steiner, Freya, Luke/Kevin (Cinna/Quina) and Deniece (Eiko). If Rydia (Marcus) is in party, is removed from the party after battles. Can recruit again anytime at Ipsen's Castle/Small Room. Completing this allows Vivi back in the Invincible Airship.
Invincible Airship Defeated Dark God/Improper Maenad. Speak with 'James' (Amarant) in the Invincible/Core. Select your desired party ally to fight battles alone.
Alexandria/Dock None Speak with Steiner at the dock and accept the hunt for Lavos.
Burmecia Accepted Lavos Hunt. Steiner and Freya both in the current party. With Steiner and Freya both in your party, venture through Burmecia to find and defeat Lavos.
Burmecia/Palace Defeat Lavos. Party average Level: 70+ Defeat Lavos and return to Alexandria/Dock. Speak with Freya and collect your bounty. Obtain: Equipment, key item and weapon equipment.
Burmecia/Residence Defeated Lavos and collected bounty for hunt. Return to Burmecia after defeating Lavos and collecting your bounty for the hunt. Speak with Freya in one of the residences and begin the long extra scene.
(Burmecia) (Freya, Ian, Kain Highwind and Sir Fratley scene) Freya in the party. A Final Fantasy IV contribution, explore through this recreated scene of Kain's Tale from Final Fantasy IV: The After Years. There are 5 battles fought throughout.
(Burmecia) Dark Dragoon #1 No Game Over Scenario battle. If player is KO'd, battle does not result in Game Over.
(Burmecia) Nia (Beatrix) None Defeat Nia (Beatrix).
(Burmecia) Kraken/Octoleech Party average Level: 60+ Defeat Kraken. Battle is not a scenario battle.
(Burmecia) Dark Dragoon #2 No Game Over Scenario battle.
(Burmecia) Dark Dragoon #3 Party average Level: 65+ Defeat Dark Dragoon. Finish scene. Reward: Whale Whisker weapon.
Madain Sari Defeated Golbez. After defeating Golbez, return to Madain Sari and venture through the ruins overrun by Gods and Angels. This scene is required to unlock New Game+; an extra scene.
(Madain Sari) Samuel/Xuchilbara/Lobsel Vith Party average Level: 85+ Defeat the 3 Gods and Angels. Complete scene. Obtain: Ring of Renewal, Black Garb, equipment and key item. Battle: Philodendron/Dendrobium fought by catching 99 frogs in the Marshland and found on the world map becomes feeble afterwards.
Marshland Catch 99 frogs. Defeat Philodendron/Dendrobium. Party average Level: 80+ After catching 99 frogs, defeat the Philodendron/Dendrobium Master Quale spawns. Reward: Equipment.
Memoria/Recollection Defeat Lord Atomos. In the Memoria/Recollection (Raining), defeat Lord Atomos and report back to Montblanc. Benefit: Freya learns ability: Nox Dragon if not already learned during Disc 3. Bounty received from Montblanc.
Abandoned Site/Mognet Central Defeated Lord Atomos. Speak with Montblanc after defeating Lord Atomos. Obtain: Equipment.
Memoria/Hades Defeat Hades. Defeat Hades before 24 hours of game time and recieve weapon: Ultima Blade.
Crystal World/Depths B3 Defeat Ultima. Defeat Omega Mark XII. Party average Level: 85+ In the Crystal World, interact with the Amdusias and defeat Esper: Ultima and Omega Mark XII. Reward: Weapon, Mina.
New Game+/Iifa Tree Defeated Samuel/Xuchilbara/Lobsel Vith. After completing the game, if conditions are met, New Game+ will begin. Setting the focus on Steiner, venture inside the Iifa Tree and experience the unheralded, censored abstract.