History Main / BonusDungeon

* ''VideoGame/Persona4'': This is played with in the Golden version; if you maxed out the Aeon Social Link before clearing [[spoiler:Magatsu Inaba]] and then ask Margaret on January 2nd to look for Marie, you will unlock the Hollow Forest. While it's possible to fight the TrueFinalBoss even without unlocking the dungeon, the player ''must'' clear it if it is unlocked and doing so is a prerequisite for the GoldenEnding.

* ''VideoGame/Persona4'': In the Golden version, if you maxed out the Aeon social link before New Year's Eve, you can enter the Hollow Forest on February 13...and ''only'' on February 13. If you don't do it on that day, not only is it gone, it's RetGone.
* ''VideoGame/Persona5'': In the Royal version, if you maxed out the Councillor confidant, you gain access to the third semester and the final Palace, the [[spoiler:Laboratory of Sorrow]]. This also unlocks a new area in Mementos.

* The UsefulNotes/PlayStation translation of ''[[VideoGame/{{Gauntlet}} Gauntlet Legends]]'' had several of these, including one-level versions of every stage that got cut from the [=PS1=] version. However, after all the [[BonusDungeon bonus dungeons]] composed of stages cut from the arcade version, the game had as its final hidden stage... [[EasterEgg the building the developers made the game in]]. The sole enemy? A giant hamster, the development team's "mascot."

* The Cow Level in ''VideoGame/DiabloII'' (and the ''Hellfire'' ExpansionPack for ''VideoGame/{{Diablo}}''), inserted as a response to a rumor from the original ''VideoGame/{{Diablo}}'' that such a place existed. Later, the 1.11 patch introduced an elaborate Pandemonium quest with several bonus dungeons.

** Once Jimmy has 100,000 dollars on his [[InGameBankingServices bank account]], he can be invited for the luncheon for the Platinum Club members at the Accelerated Dynamics building. After leaving the luncheon room, he can enter the elevator, going to the higher floors of the building, only for the lights to flicker and the elevator releasing Jimmy in the office room, with the endless seas of cubicles. Despite being very mundane in appearance, with the enemies being the regular office people (along with [[TheLastOfTheseIsNotLikeTheOthers killing machines]]), it still maintains the creepy feel based on the [[SoulSuckingRetailJob disturbing monotone office working conditions]], with the background music consisting of nothing but office noises made into unsetting music track, the worker corpses hanging outside the windows, and one storage room with flickering lights occasionally flashing to replace the archive boxes with corpses and dismembered body parts. The boss of the location is [[spoiler:Mr. Grouse, formerly a friendly banker turned into a CorruptCorporateExecutive willing to murder a child just to keep his arms dealing practices a secret.]]

** In ''VideoGame/TouhouKaeidzukaPhantasmagoriaOfFlowerView'', which is a versus shooter, the Extra Mode is unlocked after beating all characters' Story Modes. In the Extra mode, you first unlock [[TheDragon Komachi's]] story, and after beating that you unlock [[FinalBoss Eiki's]] story. Gameplay-wise, all enemies are much more aggressive than in the standard story mode, and you only have one life before you die. The AI opponent has a timer, and they're invincible before the timer runs out, upon which they'll quickly suicide and let you win.

** After freeing Sandro, the Lich-ruler of Necropolis, you get the key to the game's bonus dungeon, the [[IDontLikeTheSoundOfThatPlace Dungeon of Death]], which requires access to both Clouds of Xeen and Darkside of Xeen to enter. Upon entering the Dungeon of Death, expecting highly difficult end-game enemies... the level is instead completely devoid of any enemies at all. It is actually a giant crossword puzzle.

* Some ''VideoGame/DragonQuest'' games have added bonus opportunities as well, in each main series game starting with V and each remake starting with III.