The Skeleton Key is a unique Daedric Artifact in The Elder Scrolls II: Daggerfall. The power of the Skeleton's Key is very simple, indeed. With it, any non-magically locked door or chest is instantly accessible to even the clumsiest of lockpickers. A particularly skillful lockpicker may even open some magically barred doors with the Key. The two limitations placed on the Key by wizards who sought to protect their storehouses were that the Key could only be used once a day and it would never be the property of one thief for too long. Some of those who have possessed the Key have made themselves rich before it disappeared, others have broken into places they never should have entered. Once a day this key allows one to open one non-magical lock, or a good chance at opening a low level magical lock.
The Skeleton Key is not a misc. item but an amulet, allowing it to be worn.
The Skeleton key (when worn) gives 15 extra points to the Dodging skill. When used it instantly opens one non-magical lock per day. If the lock is magical the chance will not be guaranteed to open but is still very high
The Skeleton Key can be acquired by completing Nocturnal's Quest.
Nocturnal can be summoned on the 8th of Hearthfire. Upon speaking to her she guides the hero to a radiant dungeon to kill a mage. The hero has the option of sparing the mage's life and accepting a sidequest to get another artifact from a different dungeon, but this is not necessary and counts as betraying Nocturnal. Upon completing the task he appoints them to another radiant town in the region where they will find her Worshipper who awards them with the Skeleton Key, betraying the Daedric Prince or not.