Cosmopolitan (3.5e Feat)
From D&D Wiki
Cosmopolitan [General, Regional]
Some lands in Tirr have complicated cultures and social castes, and often, this can make understanding and communicating with others difficult, especially when they are prone to deceiving you, for some reason or another. This could be because they view your worship or deity as heretical, because you're of a lower social caste, because they do not wish to be overheard, or simply because they do not like you. Alternatively, you could simply be one of the various half-blooded races of the world, which tend to receive this treatment almost universally.