It can be obtained from Mercer Frey at the end of the Thieves Guild quest Blindsighted. In order to complete the remaining quests for the Guild, the Skeleton Key must be returned in the Twilight Sepulcher.
The Skeleton Key can be used like a regular lockpick and can be kept indefinitely, provided it's never returned to the Twilight Sepulcher, during the mission "Darkness Returns." In addition, the Lockpicking skill will still increase when a lock is opened (removed in patch 1.4, back by 1.9). Keeping the key effectively renders the Lockpicking perk Unbreakable entirely obsolete, as well as most of that skill tree.
- If the Dragonborn serves time in jail, the single lockpick taken with them to jail will be the Skeleton Key.
- This artifact is how Mercer Frey is able to break into many places with ease, such as Snow Veil Sanctum or Irkngthand. This also includes the vault located inside The Ragged Flagon - Cistern, home of the Thieves Guild. Mercer Frey was able to enter this vault, which was said to be "the best puzzle lock gold could buy," and that under normal circumstances would require two keys to open.
- Despite this, the Dragonborn can't make use of this on any puzzle doors or doors requiring keys.
- In real life, a skeleton key (or passing key) refers to a key which can open any door, as shown by what Mercer Frey does with the key.
- Although the Skeleton Key is a Daedric artifact, possession of it does not count towards the Oblivion Walker achievement since it does not have its own quest.
- If the skeleton key is spawned via console command, it does not act like the normal skeleton key, it acts much more like a retextured lockpick that can break, which makes the spawned skeleton key lose usefulness.
- However, if the Unbreakable perk is used in conjunction with the spawned key (10F13F), then the lockpick will then become fully functional and will not break (This is because the perk removes the ability for lockpicks to break).
- Dungeon Lock Outs cannot be entered with this key, as it still counts as a lockpick.
- The Dragonborn can easily keep the Skeleton Key until the perk Unbreakable is unlocked, a perk which requires 100 in the Lockpicking skill tree. There are several places where lock picking can be increased, such as the training chests in the Thieves Guild, and the several locked display cabinets in the Dwemer Museum.