Koryo Hall of Adventures OSR Conversions Document Published!

I just thought I’d drop a note mentioning that my OSR Conversions Document for the Koryo Hall of Adventures book has been published. 

For those who don’t know, Aurélien Lainé (another expat in Korea) published a 5E-compatible setting book based on Korean history and mythology. It was a crowdfunded project, and was published this year as The Koryo Hall of Adventures. (The book is now available from the publisher’s website.)

By the way, on the publisher’s website I’ve been posting a series of posts titled “Appendix K” on different Korean media—music, books, movies, and TV shows—that could be inspirational for anyone running a game in Jeosung, the default setting of this book. Aurélien also hired me to create an OSR conversion guide for the setting, and that has now been published. It’s available on the Koryo Hall of Adventures website for 4.25.  

While it’s obviously a supplement to The Koryo Hall of Adventures rulebooka really interesting RPG book worth checking out—the OSR material in the conversions guide is designed to work out of the box relatively seamlessly with any OSR system. In fact, the document includes quite a few things that would be fun to integrate into any OSR game even if you weren’t running a game set in Jeosung, the setting for The Koryo Hall of Adventures.

The design philosophy I used was to maintain as much of the feel from the original as possible, so that GMs using systems with, say, more sparse character ability advancement could strip out bits, instead of GMs having to create more for systems with a richer set of ability-advancement options.  

Here’s an overview of the contents within the document:

An Introduction to Jeosung: This includes an overview of how to adapt the setting to the range of tones and styles more common in OSR, since the hardcover has a much more “heroic adventure” tone. It also includes tips on infusing the setting concept “Obangsaek” (the five elements of earth, wind, fire, water, and mind) into your own setting.   

Three character classes:

    • The Jaein: a “bard”-like class based on Korean minstrel traditions. These characters have magic powered by masks, music, and dance, as well as acrobatics and animal mimicry.   
    • The Sunim: martial artist monks with powers driven by “obangsaek” (the five elements of earth, air, fire, water, and mind).1
    • The Mudang: spellcasters based on traditional Korean shamanism, with magic powered by multiple spirits supplicated in rituals and bound to the mudang. (Think of magicians in Jack Vance’s Dying Earth books binding multiple chugs and sandestins, and you have the basic idea.) 

Monsters: A complete OSR-styled conversion of all the creatures in The Koryo Hall of Adventures rulebook, including detailed writeups of each creature and suggested treasure. 

Magic: Complete writeups for every spell and magic item published for The Koryo Hall of Adventures (including conversions of Andrew T. Ha’s supplementary spell PDF). The text also includes some artifacts and a set of tables for determining the specific quality (and fun/challenging twists) for mudang-created charms (which are basically minor animal-magic talismans). 

Equipment: A rough guide suggesting approximate equivalent values for items common in Korean-styled traditional markets found in the setting. 

Mudang Spirits: An extensive random table-driven system for randomly generating interesting and unique nature spirits, either to add to a mudang’s spirit roster as they level up, or for inspiration in creating spirits used in adventures or encounters. Includes methods for generating personality, appearance, portfolio, and preferred jesa (sacrificial offering) for spirits at four different power levels. 

There’s even a random table for determining which musical instruments and styles a Jaein has mastered, either for players who prefer to determine things by randomly rolling, or for filling out a Jaein NPC. 

I dare say most of this material is filled-out enough that anyone running an OSR game could probably pick it up and use it even if they weren’t quite ready to take the dive into a complete detailed-setting book—even though I think the core rulebook is worth checking out, and has lots of interesting material to draw upon for anyone interested in a Korean-flavored RPG game.  


  1. This is a riff on Kevin Crawford’s excellent “Vowed” class from Red Tide.

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