Promises to Keep: Help Louis Letrush get Frost from Sibbi Black-Briar.
In this quest, there are multiple chances to persuade people (the guard and Sibbi, twice). How much Speech is required to successfully persuade them?
The reason that I phrased the title so, instead of as "how much Speech do I need to persuade…", is because I know that the Amulet of Articulation is an alternative to Speech, thus there are alternatives.
Best Answer
Both persuading the guard to let you in and persuading Sibbi to give you the key are Easy speech checks. They require 25 speech, or 18 speech and the Persuasion perk.