It can be challenging to breathe life into a fantasy world, especially if it’s a culture that’s not a fantasy analogue of your own. One of the major challenges can be the material culture of the imaginary society you’re describing. For example, while every native English speaker has a picture of Victorian society in his or her head, most don’t know what an antimacassar is, and if they do, they don’t know why it’s called that—or why they suddenly appeared all in mid-19th century Britain. In modern depictions of Victorian society, you don’t see the majority of men walking around with their hair so heavily oiled-up that cloth needs to be draped on the backs of chairs to prevent everything getting stained!
Of course, one take-home lesson from this is that you don’t need to (and really shouldn’t) shoot for absolute historical veracity: even if you could achieve it, a perfect representation of the past would just be bewildering to most people, especially across cultural differences. That said, the right “telling details” can do a lot to make a culture come to life. We already know this, as RPG enthusiasts—equipment lists have been a part of our games since the beginning.
Classic fantasy RPGs have tended to assume a vaguely European cultural setting, and so have been able to gloss over the broader material culture somewhat: players and gamemasters alike could gloss over that, taking shared assumptions about historical European cultures for granted. But in a fantasy game where the setting takes inspiration from Korea, particularizing things a little—including the right “telling detail”—can really help particularize and bring the culture of the setting to life, in the same way that the occasional foreign word can lend authenticity to dialog in a novel set in some distant land, or in some future society.
The Koryo Hall of Adventures definitely offers material to support this, especially in the vivid images of instruments, shrines, and buildings it contains (on pages 44–51). However, for those who’re less than familiar with Korean culture, I think the National Academy of the Korean Language’s An Illustrated Guide to Korean Culture: 233 Traditional Key Words is an invaluable resource.
It follows a rather unorthodox conceptual scheme: instead of being about foods, or cultural objects, it was written as a list of 233 "keywords": many of these are tied to material objects depicted in photographs on the book’s pages, but others are concepts of cultural importance. The authors took care to select concepts and objects of great importance within Korean culture—and imaginably their analogues would also be important in Jeosung culture. Making a creative effort to include a few of these items, or to ask yourself how these items or concepts might change in a world suffused with magic, can both inspire you in the development of your own adventures, and lend an air of verisimilitude to the Jeosung you create with your players.
Take, for example, the following examples selected at random:
- Daenggi (pg. 148–149): a type of pretty hair-decoration used by both sexes to ornament their hair, and associated with one’s status as a juvenile or as a bride. What if an ancient witch or antagonist managed to enchant a set of daenggi to achieve longevity? What if an aging player character found an enchanted daenggi and tied it to his or her hair? What other powers could be enchanted into one (or a set of) daenggi?
- Sang (pg. 196–197): a table, typically short-legged and designed for use by someone seated on the floor. Might one be enchanted, to lend greater flavor to food served on it—or to perform magical poison detection, or to confer magical benefits to the eater of such food? How might one add a dangerous trap to a sang, taking advantage of its low-to-the-floor design?
- Baegil (pg. 226–227): the celebration of a baby’s continued survival and growth, a hundred days after the child’s birth. What adventure-generating intrigue or disruption could occur during the Baegil of a royal or noble child? Do the foods served at a baegil feast somehow magically attain the power to ward off evil, and if so, can desperate adventurers who are being pursued by a demon through the streets of an unfamiliar village benefit from dropping in such a party, if they stumble across one?
- Bokjori (pg. 259): a bamboo strainer shaped like a dipper, traditionally hung on the wall on the last night of the year as a good luck charm: as the strainer could be used to scoop up and wash rice, it symbolizes scooping up innumerable amounts of good fortune. But what if cursed bokjori were distributed by some mysterious antagonist in a player character’s home village?
- Juldarigi (pg. 274–275): a traditional team-based tug-of war game, often played in villages around the middle of the first lunar month of the year. The rope could be cut into pieces (and used for all kinds of lucky or propitious purposes: composting for a good harvest or, for fishing villages, a good catch, and so on). Alternately, the rope could be kept intact and wound around a stone at the village entrance to ward off evil. Does the tug of war game infuse magic into the rope, or is this superstition? What happens if tokkaebi (or other antagonists) steal a village’s blessed rope?
While you need to exercise caution—your game isn’t a college course in Korean traditional culture, after all—weaving concepts and objects of interest into your game scenarios can do a lot to bring the setting to life, and with An Illustrated Guide to Korean Culture you’ll even have images handy to show players when a relevant item comes up!
An Illustrated Guide to Korean Culture is currently out of print, but is likely available to you via interlibrary loan: here is a link to the book's page on Worldcat.
If you prefer a print edition, Abebooks has several available secondhand (albeit with an incorrect cover image).