Lately, I’ve been working on a secret project to make a new, expanded version of the Traveler’s Guide to the Hamato Islands gaming guide that I published last year on DMS Guild. Having “eaten my own dog food”, I realized that I need more stuff: encounter tables, expanded details on certain items, regional information, more treasure, etc. The sorts of resources a DM needs to make a proper campaign in a given setting.
So, while working on this new project, I have ran into an interesting cultural snag: A lot of magic items in D&D lore aren’t relevant (some don’t even exist) in a medieval Japanese setting, while other items in medieval Japanese culture don’t exist in any Dungeons and Dragons material.

Take shields for example. They were not used in medieval Japanese warfare. It doesn’t even make sense to provide them in such a setting. Similarly, boots as we know them in a medieval settings weren’t common in medieval Japan either, but Japan did have geta, zōri and waraji.
Another surprisingly tricky example is holy water, which is used in some spell components (e.g. Protection from Evil and Good) or as a weapon against the undead. The very concept of holy water is a very western, medieval-church concept that doesn’t really have a good equivalent in Japanese religious tradition. You could use salt, which was used to banish evil, or possibly use omiki (お神酒) which is rice-wine offered to the kami in Shinto religion.
Yet another example are magic wands. The very idea of a wizard in medieval Japan requires some careful thinking (onmyoji are a close equivalent, but definitely not the same), and even onmyoji were not depicted using anything like a magic wand. The very concept isn’t really found in Japanese culture until you look at foreign imports like Harry Potter. On the other hand, onmyoji “wizards” did rely on tools such as the luopan (raban in Japanese) for divination, ofuda to bind demons and evil spirits and so on.
Magic rings? Sorry Frodo! Ring-shaped jewelry just wasn’t used.
None of this is to blame anyone. The original creators of Dungeons and Dragons built the game for European medieval warfare, and what they knew culturally. It’s impossible to account for every religion and every culture in such game-design, but it also shows that as the game has evolved and grown, the original model for weapons, armor, and magic items doesn’t always fit seamlessly when dealing with other medieval cultures.
It’s a fascinating problem to solve, and my efforts in writing the Traveler’s Guide to the Hamato Islands have been to bridge this gap, to translate lore and items of one culture into something that works in another setting.
Here’s a few examples of how I’ve tried to solve this issue.
The Dungeon Masters Guide provides a good translation table for medieval weapons into Chinese/Japanese equivalents in its section on “Wuxia” adventure settings. Granted, Wuxia is specific to Chinese culture, but the conversion chart works pretty well and the only quibbles I have are too specific to be worth making separate weapons for. Longswords are katana, shortswords are (in the Traveler’s Guide) kodachi, and scimitars are wakizashi, greatswords are (in the Guide) nodachi and so on.
Armor is a tougher subject that I’ll treat in a separate post.
Magic wands can be substituted for Japanese shaku, which are in turn based on Chinese hù (笏). This is not a 1:1 comparison, but since this is a fantasy setting, it’s not unreasonable to make a magically enchanted version of a wooden scepter. Similarly rings can be substituted in the case of Japanese culture with ancient magatama jewelry (i.e. jewelry you wear that’s magically imbued). The Necklace of Prayer Beads might be equivalent to a Buddhist rosary. Other necklaces probably could go either way.

While staves largely stay the same, the Buddhist shakujo can be incorporated where appropriate, along with the Buddhist robes (okesa). The idea isn’t to exploit other religions and cultures, but get familiar enough with them that you can make reasonably accurate representations in your setting.
Spell components may need to be updated as well where relevant. Using the example of Protection from Evil and Good, we can substitute omiki for now, and the licorice root used in the Haste spell might get substituted with a local root plant such as daikon or burdock root. The “powdered corn extract and a twisted loop of parchment” for Rope Trick can be substituted for powdered rice and twisted loop of mulberry paper among other ideas, and so on.
Coinage in medieval Japan still breaks down in the basic units of gold, silver and copper, but the style of coinage, and the denominations don’t always map easily to Dungeons and Dragons. Then again, neither does medieval British coinage.
These are just a few examples, but hopefully it will help fellow gamers trying to expand their D&D settings to other cultures to take into account local trends and material culture to help create a more rich (not to mention accurate) representation for your players. It takes effort and research, but makes a pretty rewarding experience too for everyone!