A key part of Gor is the idea of transplanted cultures. At unspecified points in the past the Priest Kings appear to have swept up samples of human cultures on Earth and to have brought them to Gor to found their own cities, settlements and empires.
Amongst these are the Greco-Roman culture that dominates civilised Gor and the islands, the pre-Christian Norse culture in Torvaldsland, the Shogunate Pani Islands, the Native American culture of The Barrens, the Mongolian Tuchuks, the Bedouin tribes of the Tahari and the Zulu influenced empire of Bila Hiruma in the jungles of the interior.
Conspicuous, so far, by their absence are Chinese influenced and South Asian influenced cultures (though Bazi may be influenced by either or both). For those players wanting to create a new or different Gorean culture this – and the uncharted territory of the world – create a real opportunity to make your own spin on the Gorean world, both of which have the potential to fit in very well with the caste culture of the broader Gorean world. There’s hints of a lost Mesoamerican culture, hidden in the deeper parts of the jungle as well.
Besides those areas, many cities are barely described and offer only the barest hints as to their nature. Harfax’s anglo-saxon names suggest something of a medieval English culture while the seeming etymology of other Gorean settlement names has its own hints that could be developed.
If there’s a period of history that you are particularly interested in you should be able to find an excuse to include it in your games, making Gor an extremely adaptable and open setting, if you choose to step beyond the bounds of the official material.