Writing fantasy games, or fantasy fiction of any kind, sometimes requires a look back into history. I've done a lot of research into medieval flour mills, funerary customs, ancient cartography, and all sorts of other topics that would puzzle anyone reviewing my search history.

For the most part, writing for fantasy is about avoiding anachronisms that take your readers out of the moment. Sometimes, though, you hit items that seem to break that.

My favorite example is the name Tiffany. This seems a very modern name, and a medieval or fantasy character named "Tiffany" seems improper in context. But the name is actually quite old; it dates from the 12th century, and wouldn't actually be inappropriate or out of place. Another good example is billboards with images of celebrities endorsing products, encouraging people to buy them. This is something you find on modern highways, sure, but they were also pretty common in ancient Rome (famous gladiators would make a lot of money on these endorsement deals).

This goes the other direction, too. Forks aren't actually a modern invention, but they're fairly modern in use. Forks weren't really used in northern Europe (and particularly Great Britain) until the 18th century. People knew about them for about 200 years before that, but they were seen as an "unmanly Italian affectation" that weren't in common use. Another surprisingly recent invention are doorknobs; the first doorknob as we know it was patented in the late 19th century. Latches were much more common before then, and door locks only for people who could afford them (they weren't common, and especially uncommon on interior doors). Putting either forks or doorknobs in a fantasy setting is technically an anachronism, but they aren't things that would cause most modern readers to bat an eye. Few fantasy RPG maps set aside places to excrete, and many of those that do include modern toilets that presume sophisticated plumbing.

Strict historical accuracy is interesting, but can in its own way be immersion-breaking. Big vats of urine to tan hides are historically accurate, but maybe too gross to include in a fantasy adventure. A series of locked interior doors is historically unlikely, but makes for great fun for the party rogue. My advice is to go with what feels like the right thing for your adventure, and don't stress too much about it--although, if you do the research, you'll find a lot of interesting inspiration.