A secret is something hidden to the player that is only accessible after certain conditions have been met, or if the player knows where to look.
This is a difficult concept to categorize with agreement from all players; taken to the extreme, almost any item container or NPC with branching dialogue trees is a singular puzzle and discovery. So please be selective when adding to this page – not everyone wants to wade through a long list. A high priority should be given to areas that can only be accessed once (such as the Outer Planes) and areas explored at the beginning of the game, when players are new to Sigil.
- See: Areas.
- The Tomb of the Nameless One is a not-very-secret area, although it is not referred to in the main quest.
- Pharod's secret stash is behind a portal in his audience hall in the Buried Village, and his crutch is the key.
- Access to the Siege Tower is only granted to those who purge themselves of all desire to enter, a secret learned from Lazlo in the Lower Ward market.
- The Player's Maze can only be reached by mocking or praying to a doll of the Lady of Pain repeatedly, by killing number of Dabus, or by becoming disciple of Aoskar.
- The Modron Maze is a secret area that can be accessed after a few conditions are met: the Metallic Cube must be purchased from Vrischika's Curiosity Shoppe; TNO must learn from the modrons in the Brothel for Slaking Intellectual Lusts that the cube is a portal and key; the figurine must be manipulated in the proper order.
- Do not go through the exit from Curst in the Dump to the Curst Underground until through with the quests there – it is a one-way exit.
- Leaving Curst Prison and returning to Curst Underground can cause a bug in Curst in Carceri.
- Adahn is a person manifested solely by the power of belief; the Nameless One must mention the name "Adahn" multiple times for Adahn to appear in-game (this increases Chaotic alignment and interferes with two other rewards).
- Recruiting Ignus is as a companion is somewhat complicated: the Decanter of Endless Water must be retrieved, and its command word must be learned.
- Xachariah was the companion of a previous incarnation of The Nameless One.
- Nordom is a secret companion only found in the Modron Maze.
- Vhailor is another companion, found behind the portal leading out of Curst Prison.
- A Lim-Lim can be turned to stone by Marissa in the Brothel for Slaking Intellectual Lusts, but only with a certain dialogue path (bug); the stoned creature can be traded to Giltspur for the password to the Anarchists faction shop.
- See Items.
- The Ancient Copper Earring can be opened after it has been obtained from Zombie #79 on the Mortuary 3rd Floor.
- The majority of tattoos only become available when certain conditions are met.
- One of the bodies in the pool of blood in the Crypt of Dismemberment in the Catacombs is the adventurer Lowden. The body is bugged in the unpatched game, but was intended to be able to be spoken to with the Stories-Bones-Tell ability that TNO acquires soon after visiting the Catacombs. Qwinn's Fixpack makes the body much easier to select.
- The Justifier is a hammer that can be pick-pocketed from Nadilin in the Great Foundry of the Godsmen. The weapon has dialogue, especially when "used" in the Outer Planes.
- Access to a stash of items including Spiked Gauntlets of Ogre Power will be given to Anarchists that speak with a skull on the shelves that Morte was confined to, in the Lower Ward Wrecked House.
- The Ancient Scroll is very hard to find, in a tiny container in the Carceri Warehouse.
- Up to three copies of Trias' Celestial Fire weapon can be obtained, see Curst Prison. This is mostly for fun, as at least one copy cannot be used, and the weapon can only be used by TNO.
- See Attribute.
- The answer given to Mebbeth in Ragpicker's Square determines the bonus that Ravel later gives; the most beneficial answer is, "Because I want power."
- Save the intestines that Marta extracts from TNO in the Buried Village; Ignus can use them later to grant a bonus and an Infernal Shield scroll.
- Xachariah's Heart grants a dexterity bonus.
- Vhailor can grant a strength bonus, dependent on lawfulness.
- One of the choices of rewards from the Ancient Scroll is a bonus to any attribute.