I have used in my campaign civilizations that were monotheistic, in that the people of that area believed that only one diety existed. The world as a whole was not monotheistic though, and other dieties existed.
Diety and Demigods puts forth two instances that are 'not traditional d&d' One is a Monotheistic diety, and the other is a set of two dieties, which I guess could just be combined for a two aspects of one diety thing for a monothiestic religion, similar to the 'holy trinity' thought line of the Catholic Church. (Catholic, not all christians, and not saying its wrong, or that Catholicism is a poly religion, etc...)
Anyway, it worked well, the group/land mass of peoples that were monotheistic eventually declared a holy war against the other land mass/countries, as they (believers of a poly system)were seen as tainted by evil demons, liars, thieves, descievers, etc...
RX
Diety and Demigods puts forth two instances that are 'not traditional d&d' One is a Monotheistic diety, and the other is a set of two dieties, which I guess could just be combined for a two aspects of one diety thing for a monothiestic religion, similar to the 'holy trinity' thought line of the Catholic Church. (Catholic, not all christians, and not saying its wrong, or that Catholicism is a poly religion, etc...)
Anyway, it worked well, the group/land mass of peoples that were monotheistic eventually declared a holy war against the other land mass/countries, as they (believers of a poly system)were seen as tainted by evil demons, liars, thieves, descievers, etc...
RX